The obvious way is to clean and rewick.
With a standard build no way around it, I usually stay with the profile of the juice and its not bad so if I am vaping creamy dessertish stuff and switching to the same realm it isn't a bad transition.
Fruity stuff with fruity stuff but your hosed if you are switching from cinnamon or menthol both I call contaminators
If you have a temp controlled device I usually wait until I can tell its about done and I bring my temp below 400 and it will vape it dry with no transition at all but that's only with temp devices..