JD 5420 air conditioner not blowing on both sides

[sandpat]

2003 John Deere 5420. The air conditioner is blowing full force on the left side, but just barely blowing on the right. I know I need to remove the top of the cab, but I'm not sure how many screws are holding it on and where they are located. Is there a seal that I'll be breaking when I remove the top? Any advice on how to go about this? I've never taken the top off of a tractor cab before. I did see an older post about a forum member who removed the top and found an obstruction under one of the motors, so I'm hoping thats all I find wrong. Any advice will be appreciated. Thanks.