Just do it gently, it has a spring so once the lock is released by you fingernail it will open itself. Don't worry too much, just don't cut your nails for a few days


~Stone

Mamiya: 7 II, RZ67 Pro II / Canon: 1V, AE-1, 5DmkII / Kodak: No 1 Pocket Autographic, No 1A Pocket Autographic | Sent w/ iPhone using Tapatalk