having trouble with the drive belt on a murray rider model 46576x92 17.5hp I can't figure out by the tear down diagram thank you bigpoppy52

Hi,
The parts breakdown is here:
http://www.outdoordistributors.com/pdf/Murray/MURRAY-MODEL-46576X92A-LAWN-TRACTOR-(1999)-PARTS-LIST.pdf
And the nuts labelled as #2 must be loosened to make the belt get past the guides built into the part #11. The park brake must be locked to remove tension from the belt.
Peace,
Clarke