You won't need the BFH and risk ruining the other drum if you back off the adjuster first so that the shoes diameter is smaller than the ridge that you are talking about.

Pull the rubber oval plug on the backing plate and put a fairly large strait screwdriver (there is a special tool for this, but it isn't a necessity) in and turn the star up. I sometimes helps to put a little screw driver in beside to push the adjuster out of the way so that it can spin freely. This porbably doesn't make much sense, but you can look at the other side that is apart and figure it out.