FYI, you don't have to do this with your in-camera paper. You can just make a negative and use a contact printing frame to smash it face to face with another piece of paper. It is just like making a contact print or proofsheet. And you get more control of contrast that way, and can burn/dodge.

Especially since you are in a group lab, this would probably be a preferable way to go about it. At least until you set up your own darkroom...and for the reversal procedure, it literally just needs to be "A Dark Room," with some trays in it. No enlarger necessary.