Are those bolts around the pto a removable plate?  If so it might not be to hard. 
I had to change the pto clutch on my 2520. If I remember correctly it was over 20 hours in labor just to disassemble to get to the part. Hope you don’t have to. 
I will look at mine and the manual when I get a chance and see if I can offer any insight. 
I just changed a leaking seal in my front mount snowblower. Took 2-3 hours and I was surprised how much I had to disassemble to get to it. Note to self, don’t accidentally snowblow a garbage bag full of empty cans.