I have a 5500 which is the predicessor to the 755. So "assuming" the seat is the same, there is a lever just forward of the out-rigger levers (if yours are in the same spot). If sitting on the seat facing the steering wheel, this lever is tucked in right down beside the sear on the right. Just behind the console where the throttle and key switch are. This lever needs pulled toward the seat and you can swing around backwards.
IF you cant find it, take some pics of the right side of the seat and perhaps I can better see how the 755 is set up and guide you better.