As you've figured out, raising and lowering the mast is dangerous.
There's a Hobie dealer down by Sebago Lake in Maine. Most dealers will be happy to explain how the mast hooks together. Basically there ae three parts involved -- the mast base (
https://www.murrays.com/product/50-20640011/), the mast step (
https://www.murrays.com/product/50-20200011/) and the mast hinge (
https://www.murrays.com/product/01-3021/)
One end of the hinge is permanently attached to the step. The other end of the hinge goes through the mast base. There's a pin you can use, but I usually use a Phillips head screwdriver. Harder for me to lose and has a handle to grab it. The pin can definitely pop out.
Matt Miller of Hobie did a video of setting up a Hobie. Part 1 (
https://www.youtube.com/watch?v=1VeBZOCJCoY) has putting up the mast. It shows hooking up the pins and placing the mast bearing in the cup.
Jim Clark-Dawe