you *can* wiggle the tube off, but honestly there isn't much of a point. and doing that repeatedly with time will mess with the integrity of the seal and create leaks (speculating based on my experience with other clearos). The only thing it does is speed up the 'drying' step below.
just flush it with the hottest water you can get from under the tap for a minute or two, then soak in ethanol (vodka, PGA, whatever) for a few minutes to get rid of the flavor. (menthols/strong flavors may require longer). if you plan on refilling with the same flavor, or don't care, the booze step isn't necessary.
Vinegar is a reasonable substitute if yo don't have the booze.
Flush out the vinegar/alcohol with hot water. Let it dry.
Then dry burn (3 second pulses. use a low voltage device if you have one to be safe). Once you see red, and the coils look like coils again and all the black crap vanishes, you're good to go. If this process produces ash, you may want to either flush with hot water again, or drop some PG on there and burn it off.
Honestly I've refilled onto an ashy set of coils before and the nasty ash taste vanishes after about two hits.
