The trunnion coupler just pulls apart,no bolts,no set screws,nothing. There are two big o rings that keep it sealed,that might be what they mean by "breaking it loose". The rear motor mount bolts are on the sides of the bell housing. I THINK it's that square hole that your battery cables run through,that's where you get a wrench in to hold them. Look down in behind the starter,you'll see them. One on each side. Once you see the one by the starter you'll know where the one is on the other side.
Those four motor mount bolts are all that holds everything in. Which side are you trying to get to the brake? They're a tight fit,but taking a wheel off would be easier than taking the cab off.