Naturally, this wasn't going to work for regular typing, but the fix for it was easy. Here's how to do it.
Step 1: Pop out the key
Step 3: Fold and insert
Step 4: Trim to fit
Step 5: Put key back in the keyboard
Test out the button and see if it's responsive now. If it's working, but it feels a little stiff, then pop the key back out, trim a tiny bit more of the straw off, and put it back in.