Some good advice:
Use a iFixit plastic card/credit card (work from the short side of the computer) and stick it under the battery towards the glue strip and hold the card approx 45° (or whatever angle is appropriate) and drip the glue remover on the card so it slides/runs down the card underneath the battery. In this way the glue remover is aimed straight to the glue under the battery to ‘eat its way’ onto the glue. Let it do its job for a minute or two. Then you can dig in the card even more underneath (the angle of the card will obviously be less and less as you get further in; the idea is just to somehow slide the liquid under), add a bit more remover, dig a bit more, etc…
Otherwise the glue remover can get a bit all over the place but this way it is more easily directed towards the glue.
A very good way I found when I, as probably many others, made the straps snap; a way I definitely will apply next time if I do this: use a spudger and “spinn” the white tejp out. Working with the hands trying to pull it out was not ideal… So:
Stick the tejp on/around the spudger and roll it up/out on the tip on the spudger. Once it grips hold on the spudger and you roll it, it almost eats it way out.
Otherwise it would have taken me ages to get it out but yes, if it snaps (or from start) you can get hold of it under the battery then you definitely have a substitute solution here.