Dyeing interior

I was wondering if anyone has dyed their sear inserts. I was considering dying my gray inserts black. Any thoughts?

From my experience dyeing things it sounds like it would be a mess. Trying to control the dye bleeding on to adjacent fabric would be next to impossible. Could a local upholstery shop just cut out the sections and sew in a new fabric? If you did all the hard work of pulling the seat covers off it couldn't cost too much.

Does anyone know the procedure for removing and reinstalling the fabric covers?