How do I replace the mower belt blade for a snapper model 3312x6sr rear engine mower? Is there a trick getting it attached in the rear? Is there a diagram?

Hi,
May have a digit missing in that number Snapper does not recognize it; but:

How to replace the belt on a snapper model # 7800105

Hi,
You seem to have a 30125BVE and the picture is attached. Yours are the directions for the 30" deck(first two digits of the model number.)
Peace,
Clarke