G'day
pjay53,
There's a free download of a Victa workshop manual excerpt covering these here:
https://www.outdoorking-forum.com.au/forum/u..._Engine_Parts_List_and_Ma.html#Post54967'Victa Old Starter Information' in Section 2 is the one you want.
It's a very straightforward job on a Zip starter. Just take careful note of the order of the friction washers as you take it apart.
And fuse the cord ends with a match/lighter flame to prevent fraying, if it hasn't already been done.