Subaru key fob not working after battery change

I fixed this myself, but I'm just not in a state to type up the instructions. Hopefully someone gets some benefit. I (think) all Subaru key fobs from the 2010 to 2014 range should fit into this? Anyway, the positive terminal inside the fob sheers due to wear and tear so you end up with it sometimes working if you smack the key about while pressing a button

Once you've disassembled the battery (thank you Miroslav 汽车钥匙电池更换) it'll look similar to this;

There are three small screws on my model that hold the battery in place. After removing these, to seperate the two halves I simply pushed my nail in to pop it apart

I didn't plan on making this otherwise I'd have taken a picture beforehand. I placed the tip of my soldering iron on the contact and globbed a bit of solder on. I trimmed a bit off the top because like I said, globbed.