soak it in hot water. ( real hot ) for 5 minutes.. then lube with some oil.. and then use 2 spoons ( eatin' spoons ) and walk it on like you were beading a tire on a rim..
leather are mostly what I've used. they worked for 50-60 years.. can't be that bad... I HAVE used the rubber ones. they DO go on easier, and have a cup side.. i won't be alive in 50-60 ys to see if they hold up the same as the leather ones.. so don't matter to me.. :)