I think I have found an easier way of changing the mufflers on Harley Trikes, once you get the old ones off
I put 5/ 16th studs in the rear holes of the mufflers
I found this easier to align them and easier to turn a wrench on than a bolt
The front bolt is not bad to start
With the stud in you can massage a flat washer a lock washer and start the nut with your finger tips, then tighten it up
I hope this helps