How I removed a blister from the card without damage by myself?

[dr_cyclops]

Answer: I let someone else do the damage to the blister and card. That makes it someone else's fault.

[Capt_Kirk]

Acetone and a Q-tip. Apply to the back of the card and allow it to soak all the way through to the glue. It will come right off without damaging the card. Just pull carefully after the acetone has been allowed to soak all the way through. The acetone evaporates and leaves the card in tack.