There are two main parts: the hoist assembly, and a rest plate. The hoist assembly bolts to the crossmember under the storage bin with four M8x20mm bolts, and an M6x10mm bolt on the metal tab at the end of the tube. The rest plate attaches under the chassis behind the bumper with two M6x10mm bolts, and has a relief and hole where the tube is attached.
Rear chassis behind bumper where tube and rest plate attach:
The bolt under the plastic opening where the rod inserts is where the tube attaches. The bolts on either side (one about 12" away, and another about 3" away where my trailer wiring is attached) are where the rest plate mounts.
Crossmember and 4 bolts:
You will need those large rubber pieces. There's a RH and LH version (arrows on them point towards front of the truck), and they attach with a large plastic push clips. These, and the rest plate, are what the tire is pressed against when winched up. I assume you already have a jack and rod, though I think older R50s had a bottle jack, while newer have a scissor jack...the rod might be different.
If you have a hitch, you're limited to about 31"-32" depending on the hitch style/shape and where the receiver tube ends.
Green Pathy: if you're looking to get all the parts in shot, shoot me a PM. I have everything, except a use for them.