Ok I've had three Myjets in rotation, 6 months old, 5 mo, and 4 mo old. The batteries in the two newest ones aren't holding a full charge, vape is weak and I've cleaned all terminals. The oldest is still going strong and it's a different style- the one with no air holes visible until I drilled one. Has anyone taken one of these apart? I'm thinking of seeing if I can find a replacement battery... though for the cost of buying a soldering iron I can probably by a new myjet.
I did when one of mine died due to "possibly leakage" I don't have any pictures of it sadly
its basically a battery tray that slides out the bottom.
one concern I have about disassembly is there appears to be a glue around the bottom where the charge terminal bit is.
that particular piece is actually separate from the battery sled and has another silicone bit that kind of holds the diaphragm sensor for activating.
The bottom piece and the sled sort of clip together.
Ignore my terrible paint skills, but its something like this if I recall, but I threw it away a long time ago. I also didn't draw/account for the other little electronic bits since I can't remember what it looked like.

Assuming you can even find the battery you want to replace its probably not worth the effort. but if its trash anyway might as well break it apart and see what she looks like.