How do you loosen a tensioner that seems to be stuck in a 1990 Mazda B2200?

I will assume you are regarding the pulley for the power steering? If so to loosen it use a socket on the top of the pulley it should have a flat head style appearance.Loosen it clockwise and then the big nut on front of the pulley is a 7/8 inch combination wrench loosen it and the pulley should slide down to make the PS belt loose.This pulley is kind of weird but,by loosening the top bolt (metric) the bolt will come up as you take the tension off.Then YOU defenitely have to loosen the nut on the front of the pulley itself which alloys the pulley to move up or down.To adjust back with new belt on run the top bolt which is behind the pulley with the flat head cut in it run it down tight then tighten the nut on front of the pulley this locks the pulley in place so it will not move.Hope this helps.If this question is in reference to the tensioner for the timing belt resubmit your question.