I found the bolt under the pullies but can't get a wrench or socket in there to get it off so that I can replace the lower drive belt... There is not enough space to take it off from the top. Is there a trick to doing this or a special tool??? I don't want to take the whole mower apart just to replace the belt... It looks like the top nut is tac welded or something..... PLEASE HELP....I searched u tube etc... thank you, Barb