1) Open 2) Open by moving a sliding rod 3) Open up 4) Remove a fastener 5) Remove the lock 6) Take the latch off 7) Undo the bolt of 8) Unfasten 9) Unlock 10) Withdraw a lock 1) Undo 2) Unlock 
• (v. i.) To explain or unfold a matter; to make a revelation. • (v. t.) To remove a bolt from; to unfasten; to unbar; to open.
[v] - undo the bolt of
to open (a door, window, etc.) by or as if by removing a bolt; unlock; unfasten. · to release, as by the removal of threaded bolts: He unscrewed the nuts and unbolted the inspection cover.