I replaced belts on my old Hesston, it was a lot of climbing up and down the baler but not too hard. I just left one original belt in until I had one new belt in place so I knew the correct path to follow. You shouldn't need a crimper since your new belts should come already cut and laced. I assume you can get endless belts for your BR780? Might be the way to go.
Call this # 1-334-627-3348 Hammond Equipment Company and give them the model of your baler and he will send you belts with the ends already on. All you have to do is put them in which isn't hard and his prices are hard to beat. They will come to your door in a box.