Ive only worked on an older ride on snapper but most are the same
With the belt disengaged and spark plug out of the way there should be two steel cables or chains that connect the mowing deck to the lever thatlifts/lowers the deck. Put something under the deck big enough so that the weight is off the cables. the cables should just unbolt or slide off from the deck. In the front of the deck there is a pivot point that connects the deck to the tracter with a rod and pin that is removed by taking off the pin and hitting the rod out with a rubber mallet. after that remove the belt (just from the pulley on the deck) and maybe disconnect a few sensors if its a newer model and the deck should come off. I'm a kid and just learning as i go so my directions may not be accurate.
Good luck i'm interested to know how you do
there are some manuals at snapper.com go to the publications link