The instructions below have you basically taking ALL of the guts out of case. I’ve been doing my own apple repairs since before ifixit was a thing and this one is a handful. My battery was swelling and I wanted to remove it before it burst or bent the case so I took it out without having a replacement and it occurs to me that aside from using the solvent (liquid) to remove the adhesive, you could probably do this only taking the trackpad ribbon out. I have mine reassembled now and will research the best battery to buy but I think installation will take about 5 minutes. See if you can slip a plastic gift card under the battery and wag/saw the adhesive out without the solvent before you go through all of this. It might work. Note, don’t bend or put too much stress on the battery and certainly don’t puncture it…

This guide does not mention the step needed to separate the front glass from the rails. If you have a broken screen and have placed tape over it to hold it together, make sure you don't tape over the home button. It is attached to the part you are removing and you will tear the ribbon cable if it is taped to the front.