Original post by: Tom Shafer ,
Cut a plastic playing card the same width as the SD. Don't cut the length, leave it long. (Business cards are soft paper and too thick.) Slip it down alongside the stuck card until it seats firmly in the socket. Wiggle both cards, held together as one, when you try to remove them. Try each side of the SD card. ( It may be stuck by the contacts.) If it refuses, slice another card and make a SD sandwich. Newer devices, like your GoPro, may not allow a 'thick' card. I have used this trick many times on my old Sony camera. If this card-trick fails, you'll need surgery ! Do not try to yank/force it out. 2 years ago, we had a SD card split apart inside my laptop. The label half came out, but the contact side stayed. Since the device was part of the mainboard and not replaceable,,,, its still in there !