I do it this way; change all the system and application icons and perhaps Dock, then create a new collection. just leave it unnamed eg. New Collection and then, whilst in the New Collection, go to the CandyBar menus and choose Save as iContainer and just remember to include application icons too, or not, you decide 😉
Now you can save your iContainer anywhere on your computer.
To get to see your icons and perhaps Dock, just drag the iContainer back into CandyBar.