I have two 2015 15" MBPs, one for work and one for home. Both of their batteries started bulging within a few months of each other.
The guide was great, although I took the shortcut advice and only did the battery without removing speakers, etc. It was a little challenging, but after I did the first one the second one went much faster.
Definitely cut the tip of the adhesive remover very small. You can slide the edge of the card under the battery, then drip the adhesive remover onto the card and that spreads it evenly under the battery. And be gentle.