Hi Martin,
KF 20+ are sturdy, though, little big boats.....
My Kingfisher 20+ came with two masts: a hinged one and a one-piece one.
If you are going to lower the one-piece one tipe you'll need assistance.
The steps are:
-put the boat on the hard.
-tye the sail bundle together with a couple of straps and lower it to the deck detaching mast lift and topping lifts.
-remove sheets and halyard.
-if possible secure the upper part of the mast to a crane.
-remove the wedges that fix the mast where it passes through the deck.
-go inside and remove the floor of the forward cabin to access the mast step. The mast is secured with a bolt passing through step and mast. The bolt is parallel to the boat axis (0°-180°). Remove the aft and fore forks and the bolt.
-lift the mast out of the boat.
In my marina there isn't a crane with a separate arm for lifting masts so we made it in the launch basin.
The boat was lifted a bit to avoid rolling while the mast was loose and we were three people:
two lifted the mast standing on the deck and one stand on the dock with an extra long hook.
As the mast is on the deck and no longer vertical, the weight becomes significant and the leverage unfavorable for those standing on the deck. The one with the hook must sustain the mast and help prevent the mast from falling.
Attached below you find a picture of the mast step.
I hope this can help you.
Cheers
Mauro
PS.: you can find a lot of informations about your KF on the KYOA (Kingfisher Yacht Owner Association) website https://www.kyoa.org.uk/