Unfortunately, opening up your Apple Watch may damage the Force Touch sensor, which also serves as a gasketing seal. The sensor is made up of two layers, glued together. These layers may separate when you open your watch, compromising its seal after reassembly. If this happens, you'll need to repair or replace the sensor before reassembling your watch.
Throughout the repair procedure, as the iOpener cools, reheat it in the microwave for an additional thirty seconds at a time.
Be careful not to overheat the iOpener during the repair. Overheating may cause the iOpener to burst. Do not attempt to heat over 100˚C (212˚F).
Never touch the iOpener if it appears swollen.
If the iOpener is still too hot in the middle to touch, continue using it while waiting for it to cool down some more before reheating. A properly heated iOpener should stay warm for up to 10 minutes.
If you don't have a microwave, follow this step to heat your iOpener in boiling water.
Fill a pot or pan with enough water to fully submerge an iOpener.
Heat the water to a boil. Turn off the heat.
Place an iOpener into the hot water for 2-3 minutes. Make sure the iOpener is fully submerged in the water.
Use tongs to extract the heated iOpener from the hot water.
Thoroughly dry the iOpener with a towel.
The iOpener will be very hot, so be careful to hold it only by the end tabs.
Your iOpener is ready for use! If you need to reheat the iOpener, heat the water to a boil, turn off the heat, and place the iOpener in the water for 2-3 minutes.
Because the gap between the screen and watch body is so thin, a sharp blade is required to separate the two. Read the following warnings carefully before proceeding.
Protect your fingers by keeping them completely clear of the knife. If in doubt, protect your free hand with a heavy glove, such as a leather shop glove or gardening glove.
Be careful not to apply too much pressure, as this might cause the knife to slip and cut you, or damage the watch.
Wear eye protection. The knife or glass may break, sending pieces flying.
Using a curved blade minimizes the chance of scratching the case or cracking the glass. Only pry with the curved section of the blade, and not the tip or flat section.
Place the curved section of the blade in the gap between the glass and case on the lower edge of the watch face, and press firmly straight down into the gap.
Be very careful to maintain complete control over the knife—once the gap opens, if you're pressing too hard on the knife it may slip in and cut the battery.
This should wedge the gap open and cause the glass to lift slightly up from the case.
When the glass has lifted, gently rotate the knife down, opening the gap more by pushing the glass up.
There are two cables connecting the screen to the inside of the watch, near the top left corner. Be careful when prying or you may damage these cables.
Pry slightly up on the right side of the screen, to free it from any remaining adhesive.
Pry up on the left to free it as well—but do not attempt to remove the screen as it is still held in place by two cables.
If you can see the top layer of your Force Touch sensor among the display adhesive, it means the two layers of the sensor separated and you're going to need to replace or repair it.
iFixit screen and battery repair kits come with a replacement Force Touch sensor, so if you got one of those, don't fret.
The top layer of the sensor may be adhered to the back of the screen—if so, push it back down and separate it.
Place the watch on an elevated surface, at least 1/2" or 1 cm tall—a small box or the edge of a book will work great. This will allow the screen to hang down vertically and give better access to the battery.
Be careful not to bump the screen or strain the cables while you work.
Use scissors to cut one of your opening picks to about the width of the battery. Try not to leave any sharp corners.
Insert the modified pick between the right side of the battery and the case.
Use constant, steady pressure to slowly pry the battery up, separating it from the adhesive securing it to the system board.
Be careful not to deform or puncture the battery.
On the larger (42 mm) models, it's possible to accidentally pry at the system board underneath the battery. Insert the pick only far enough to get underneath the battery, not the system board.
If needed, apply a little high concentration isopropyl alcohol (90% or greater) around and under the battery to help weaken the adhesive.
Do not attempt to remove the battery as it is still connected.
Steady the bracket from the left side using your fingers or tweezers.
At the same time, insert a small (1 mm) flathead screwdriver under the tiny tab on the right.
Finally, place one finger behind the tab, and pinch the bracket hard between your finger and the screwdriver to detach the cover.
This releases two slotted tabs that hold the cover to the bracket, and should free the cover.
Prying the cover off can be challenging and may take more than one attempt. Be patient, and take care not to pull on the bracket or tear the attached cables.
Use tweezers to peel the outer ring off of one of the adhesive strip pads.
Be sure to get both the double-sided adhesive and the brown backing paper.
Be very careful not to fold, bend, or stretch the adhesive tape, as this will make it too thick to seal the screen without a ridge between the screen and the case.
The following steps detail repairing a Force Touch sensor with separated layers. If you're replacing your Force Touch sensor with a new part, ignore these steps.
The remaining adhesive sticker backing makes a great work surface.
Open the gap between the two layers, but do not peel apart any more of the original adhesive.
Apply super-glue to the lower half of the sensor and press the upper half down into the glue. Press hard to squeeze out any excess glue and make the sensor as thin as possible.
Set the Force Touch sensor on top of the adhesive, back in the case. Be sure to properly orient it, with the connector in the lower left corner, facing up.
Use a plastic opening tool to press it against the adhesive and make a tight seal.