In my opinion it is very hard to take of and reuse a seat cover, others may not agree. Taking off covers from a seat and reusing them espically if you have never done this kind of work before is not easy. cover material can easily tear espically around the edges and where cloth meets leather in the corners,

I redid the seat covers on my W202 C-class, I puchased a new seat cover bottom and replaced my tired seat bottom. It was a PITA, but the results were worth it for me.

To move the seat control buttons form seat to door is not something I would recommend to you.