The mechanic are relatively simple, you use your mouse to bounce the pin up, when it hits the top your have a brief point of time (unable to be edited) to right click locking the pin in place, when you have a few seconds to hit the Enter key (built in default) or the spacebar to move your lockpick forward to the next pin.
this also starts the default (and built in) timer, if the lockpick hits zero it breaks and you need to start again with a new pic.
Please Note all current pickable locks are set on the tutorial/easiest setting. which surprised the dev as well when they received the prebuilt coding for the minigame/skill test, and started testing it. and yes this will be a re-occurring thing, cause having to pick locks on occasion fit the story.