Lock handling and mainspring removal
Use a mainspring vise to remove the mainspring, compressing it with the lock at rest just enough to free it and positioning one leg near the hook of the spring so it sees the same load as in the lock. Back the vise off if the lock will be left unassembled. Use a punch to remove the tumbler from the cock, since prying will cause damage. Do not store the lock at half or full cock, which can damage the sear and tumbler.