Practically, the whole inner workings can be disassembled relatively easily, but would not be advisable:
1. loss of warranty.
2. as far as I can tell, there are very high-quality parts in SMD technology that cannot be replaced without the appropriate tools and knowledge. The professional repair could be more expensive than the market price if you add shipping and other expenses.

I wonder what needs to be repaired on this powerbank? Replacing the battery cells? There are four screws on the side for which you need special tools, then the inner workings can probably be pulled out of the transparent cover, but I haven't tried it myself yet, because I don't want to lose the warranty or break anything...

Very good and robust