You are best off taking the whole thing out and re covering it. It's a 'mare to do and annoying but doable and will look great once done. Beware though it is glued in above the drivers seat with three / four lines of black sticky stuff. You can just push your hands either side of it and the board will come away, best to wear gloves though. You can re stick it by gluing on top of the black stuff, but you really don't have to.
You can get 3mm foam backed 'alcantara' from eBay (I got some from a company who use it to fit out VW T5's etc, you will want three metres in length, but make sure it's wide enough) You just need a spray can of upholstery contact adhesive too and somewhere to work and leave it as you'll want it to dry before putting it all back.
All in it costs less than £50
You will probably want some new grab handles too as they're a 'mare to get out and basically useless afterwards unless you straighten them back out.