I have the Kubota
B1750. It does have the covers on the mower deck covering the pulleys and belts and it is designed to driver over top of it to put the mower deck on and take it off. I've done this for about 15 years.
When you take it off, disconnect the two rear pins, then the front pin, then the pto shaft (first by pushing outside further on - this releases it). Sometimes I would put a screwdriver in there, once I've released it, to pry it off of the pto shaft a little bit and then finish it by hand.
The easiest place to driver over and off is with it in the grass, otherwise it wants to roll away from you. Then I would take two 1" x 6" boards about 18" long and put from the ground just behind the front tires and the other end on top of the mower deck. Now get on, back over top slowly and just let it drop down of the other side of the mower.
Putting the deck on, again in reverse. Easiest to have deck in grass so it does not roll. Put the same two boards on rear of deck width of the front wheels. Drive over top and drop down on over the front. Attach two pins, then front pin, then PTO shaft.