Harness Mounting

[MDH06]

I've never mounted any seat belts, and when I bought this car none were installed.... However.. the car did come with some new belts. I can't figure out how they properly go. Im sure I could be creative and get them in but I don't wanna mount the improperly... The belts came with 2 huge washers, 2 locking washers, and 2 nuts.. Directly behind the racing seat on the roll cahge there is a trangular plate welded to the frame with a single hole in it.. I assumed this is for the shoulder harnesses but im having a hard tiem figuring out how to mount them. I don't see anything for the laps belts and the submarine belts... Little help?