If you're talking about the pump, you can just unhook the lines, and then the whole unit is held in place by 4 bolts through the battery/gas tank tray assembly. Pretty sure there's enough room for the unit to pull right out after you take off the pulley and belt.
For the ram, the steering tower has to come loose. It can be done without taking it all the way off...something to hold it from above is nice (a second set of hands). There is a pin with cotter pins on each end of the ram that let it loose.
If you're parting it out to sell, you should grab the ram bracket that is bolted to the BGB while you're in there. That should sell with it. Likewise, an actual, complete set will include the rocker shaft too. Those are varied slightly from a standard shaft. If you're real picky, the kit also includes the side panel from the LH side of the tractor, and the mid PTO engagement bracket that bolted to the frame.
If you are taking everything out then yeah,you'll need to pull the steering tower out to get at the rear pin on the cylinder.
I'm no expert,but just put a 3112 back together out of parts,so the number didn't mean much to me but it was similar to the 3012 and 3112 I had,I knew the 3012 I had didn't have a hydrostatic rear,but...well anyways,yep.