Be very very very VERY careful when putting the speaker back in. Unfortunately I pushed too hard and the screw hole on the lightning cable connector bent right in half. I managed to save it with some tweezers but that was almost needing a new lightning module.
The iOpener used is essentially a bag of gel, which you put in the microwave for 30 seconds. You lay this against the screen edges to transfer heat and loosen up the glue.
You could also use a hot-air blower with a re-work station but that's up to you. Mine worked well up to 150°C
Fantastic instructions. I fixed my 4S with this.
Instead of the rework heat gun, I used a flat attachment onto a soldering iron and rubbed it over the top of the chip (actually making contact). 185 Celcius, for about 5 minutes.
I did take the logicboard out and secured it in a small vice to do this.