How do you replace spring on 1966 road king kickstand?

The first Road King wasn't produced until 1994, but on a 1966 FLH to remove the jiffy stand you first put the bike on a lift to take the weight off of the jiffy stand, then remove the bolt on top of the jiffy stand leg that holds the keyhole-shaped locking tab in place.

Remove this tab and rotate the jiffy stand all the way forward. This will remove all tension from the spring, making it easy to remove and replace.