The short version:
It's not that hard but it's not trivial either.
It's very much like learning to ride all over again.

I did it by using raised 2x6s to provide a platform either side to put my feet. It's confusing as heck at first.

BTW a bike with low standover is helpful.
I had a TALL one, think French fit. Lemme tell you, I was focused 😬

cheers -mathias