Be careful here when you slide any tool under the central cells to pry them open, you could slide it under a sliver plate covering the trackpad electronics, maker sure that your tool is really sliding between the cells and this silver plate, I almost torn this apart, luckily id did not damage the trackpad, dome people reported that it did really damage the trackpad.
This is the hardest part of the whole process, if you don’t have any of ifixit tools you can use a hair dryer. Apply heat on the cell (make sur you don’t apply too much heat), flip the laptop apply heat for 20 to 30s on the aluminum side just near the trackpad( depending on which cell you wanna pry open) and use a credit cart gently. this will do.
some models have one screw on the upper right corner of the battery cells (battery circuit board), the rest are rubber feet that doesn’t hold anything. no need to replace them if your replacement battery doesn’t come with them.