[ITSv40]

As above, get a good passenger side from a scrappie.

Very simple to change:

Fully extend belt and clamp winding drum so that it cannot rewind.
Loosen webbing within drum and withdraw metal pin from end of webbing, remove webbing from drum.

Re-thread new webbing into drum - noting the same orientation as the original - replace metal pin in end of webbing and locate in drum. Hold webbing by hand, remove clamp from drum and carefully allow to rewind. 1hour max from start to finish.