If your journey started here in Oz or Sth West Pacific, the reissue fee is USD75.00. Everywhere else in the world, it's a higher fee and nearly everyone with an ex SWP origin ticket is always told the higher price. If they quote it to you, gently prod them to read the change rules for SWP origin RTW fares.
If ticket issued before 15 April, make sure your YVR and SFO stops don't put you over the 5 max stops in USA/Canada.

And yeah - it will need reissuing if you are changing the route.