Multiple things to note about this keyboard, first, the circuit board doesn't really have much holding it in place, so it might pop off. You can just put it back

second, in order so that the rubber contacts don't fall out you'll have to elevate it from the sides so that the keys are hanging and not being pressed by any surface,

with this, the body is way too thin and will bend, so use as many support points as you deem necessary, here I used a bluetooth speaker, a lantern and a roll of tape. this is not how you should do it, but, it does the trick, so whatever

Now, in order to take off a key you will need to press this 2 latches in (3rd image), and then the key can come off, I do warn you again this are fragile the plastic of this keyboard is quite cheap, some nose pliers will work in order to press them and remove it, but be careful