A punch tool assembly includes an adjustment subassembly coupled to a canister sidewall of the assembly. The adjustment subassembly includes a punch head, which engages a punch holder, or body, of the punch tool, at a threaded interface, so that rotation of the punch head moves the punch body/holder along a central longitudinal axis of the punch tool assembly. The adjustment subassembly further includes a locking member, which is biased with respect to the punch head, in a first position, where the locking member is engaged with a locking feature of an engagement sidewall of the subassembly, to lock the punch head and prevent rotation thereof. The locking member may be released, to unlock the punch head, by applying a force to an externally accessible actuation interface of a release member of the subassembly, for example, to rotate the actuation interface about the central longitudinal axis.