It would help if pictures were provided so I know exactly where it's coming apart. If I'm not mistaken, it's the glass and digitizer that is coming off? I wold imagine it is something similar to cellphones, where there is a double sided sticky tape that keeps the glass and digitizer on the front faceplate. If it's under warranty, I would suggest taking it back to where you bought it from first, to see if they will replace it. If not, Try going to
smok and see if they'll be willing to replace it.
If it's not under warranty, or you wish to try and fix it yourself, I'd suggest taking it to a cellphone repair place to see if they could help you out. Even if they say they don't repair ecigarettes, just explain to them that it's just the LCD you wish them to repair If anything, ask if they have any of the double sided sticky tape used to keep digitizers on cellphones. If you want to buy the tape for yourself, you can check out ebay or amazon. Here's a few examples..
Walmart
Ebay
Another Ebay