The bracket had been bent backwards (screwdriver and hammer) to force it of the end of the lockbar on back of lock.

That lockbar normally fits inside the "L" cutout on the bracket which just hangs there. Rotation of the key would turn the bar to move the bracket up or down. A little elbow grease and pliers and it could be bent farther back to be parallel to the drawer if locking the cabinet is not a concern.

Or: remove the lock via the nut or spring clip as mentioned in the above answer. Take the same pliers and elbow grease and bend it back parallel to the front and lift it with one hand and insert new key assembly to hang bracket as describe above.

Replacement locks are easily obtained. Compare your old one to find exact match.