Yes an extend able tiller should work.
You might try placing the mast head onto a ladder or similar before stepping onto the boat. Once on the boat, if the mast is at thigh height or higher... makes it easier.
Thanks. I will try the tiller.
I have got as far as standing on the boat with the mast on my shoulder. As I walk forward with my hands sliding down the mast and pushing the mast up, I lose control of it side to side. I saw a picture of a man stepping the mast from the side of the boat. I don't know how he got around the front and I have not tried this yet. Liz