A bit late for replying, but for the record you can unstep the mast without the gin pole - just run a line from the cockpit through a block at the bow and attach it to the jib halyard. This will serve as a forestay that you can slowly let out as you lower the mast. Then undo the forestay and have your helper(s) support the mast on the way down - lowering it aft, of course. Put a life preserver on the stern pulpit and rest the mast on this while you undo the bolt in the tabernacle, then move the whole thing forward until the base of the mast is at the bow. The tabernacle can be used to hold the mast at mid-section.
I've had good luck completely stopping the mast by using this line attached to the jib halyard to control it - even when the mast was beyond 45 degrees - by using the jib sheet winch and even cleating it off to check how smoothly things were going. Pick a calm day and things should go alright and don't let the windex hit the dock and get broken like I've heard can happen.
1964 Whitby 25
Severna Park, Maryland