1. Pry off the Tinnerman Nut at the end of the back tightening knob.
2. Unscrew the knob from the backrest clamp.
3. Push or pry the backrest clamp of the back post.
4. Repeat steps 1 to 3 for the other side.
5. Push the new backrest onto the back post.
6. Screw the backrest tightening knob all the way into the backrest clamp.
7. Push or lightly tap the Tinnerman Nut onto the end of the backrest tightening knob.
8. Repeat steps 5 to 7 for the other side.