Do the seats have to be removed to replace air lines

 

Yes. There simply so way to contort yourself
enough to do this work in place.

 

No. Move the seat all the way forward, tilt the seat back forward, and take off the back of the seat. There are just two screws at the bottom of the seat back that you remove, then nudge the bottom towards the top of the seat and lift off. The pump should be in a little leather pouch on one side. On mine, the hose was broken near where it came out of the pump.