When you raise the mast, the base of it will fit over a ball on the center cross-beam. Put the Gatorade bottle-cap in the base of the mast and put the mast up against the mast-step ball. Put the screw-driver through the holes in the mast base and mast step. The bottle-cap is a "mast bearing" that prevents metal-on-metal contact. If you try to put the mast up with no bearing in place, the holes in the base and step won't line up very well. The screw-driver locks the mast and step together and acts as a pivot, allowing one person to raise the mast.

Salty types may insist on a proper nylon disc mast-bearing, and indeed that is what I'm currently using. I leave my boat mast-up on the beach, and recently lowered the mast to work on some things and found that I'd been using a bottle-cap as a mast-bearing for the past year. It showed little sign of wear, but as I'd since found my nylon disc I swapped them.

I used dacron line to tie the forestay to the bridle. Recently I raked the mast a bit more forwards and shackled the forestay directly to the bridle.

I'll go take pictures of my boat and post them tomorrow. I might be finally putting the TheMightyHobie18 rudder system on it tomorrow...