I've been up our mast a couple of times. You need to have a second halyard for safety. We recently picked up a flexible mast
ladder and that with the bosun's chair is working well for us. You might ask around and see if anyone near you has one you could borrow.
I've chatted about options here
Sailboat Mast Climbing
I have a link in there to show how to tie the knot my buddy used to help us get him up...that might be something you'd be interested in, you can help the wench apes grinding away.
One thing I've learned about the bosun's chair is I need extra padding on the seat. They are very uncomfortable after just a few minutes. Be sure too, to have a
line from the seat to the deck in case you need something you've forgotten. That way someone on deck can hook it to the
line and you can haul it up.
Good luck and be sure to err on the side of safety! It's a long drop....