I do a total breakdown on the Z-Atty about once a week for a good cleaning. I re-coil my wick at the same time. I think you will find it hard to remove the glass with the ceramic wick installed without breaking it.
If I am switching flavors, I will syringe out the liquid I am "done" with and put it it a separate bottle (don't put it back in with your clean, new juice). Then I will fill the tank with hot water using the syringe and flush it out a few times. It's okay if you have a few drops of water left in the tank when you are done. I find this is a good time to increase my voltage up to around 5.5V and give the coil a good dry burn for a quick cleaning. Voltage back down, new juice into the tank with a drop or two on the wick up top and you're good to go.
Actually, the removal wasn't that hard at all, I didn't apply pressure to the center, but near the top, so I wasn't pressing in on the hollow part, and I gently turned it while lifting. Worked like a charm, came right off. Near the top I did take several extra (albeit possibly unnecessary) seconds to move even slower, just to make sure that I didn't hit the coil when it did finally come off. Came off without much (if any) fuss. I dry burned the coil at 3.3, then 3.5 volts after cleaning and reassembling, waiting a few moments between burns and holding it upside down, trying to force down as much liquid as possible. Seemed to work out rather well, as I didn't have any after taste from the green apple in my pear/coconut flavor, and have been enjoying it ever sense
As far as rebuilding my coil...eh...can't find any reason too, as long as it doesn't break on tear down for cleaning, and the flavor isn't changed or bad, the coil still works. Ain't broke, don't fix it seems like as good as any slogan to go with to me xD