I was bored one evening...long ago. It takes some good honest tapping along with the proper sized tool to get the sleeve out of a kanger subtank mini vertical coil too make it a horizontal coil. I have to sit down and redo it to figure it out again but YES it can be done and not damage anything. I'll wait for the day my last rba bites the dust before dwelling into rebuilding the factory coils.
The original [square] Subtank OCC was a challenge but you can get the top cap off. The vape with a single or dual horiz, far better than any vert I've ever done in any tank. Naturally, I'm talking strained and oxidized as described here.
Problem is I'm down to my last few as I pass on as many as I can to start new vapers. So if you have any of the orig that disassemble hold on to 'em. If not rebuilding, hail me and send 'em my way!
Good luck Alt and enjoy the vape.