This probably works on b6's as well.

You can wrap it in prety much anything. Most will probably prefer ultrasuede or alcantara. You can find them online for aboug 30-40 a yard which is plenty of material.
Unscrew your stock knob. You will need to dissassemble it. The top cap will pop off. and the silver ring on the bottom as well. Then you can see that the leather is a simple strip that is just stretched to conform. Then pull the leather off. If you want to get it right the first time, just unstitch the factory leather and use that as a pattern. If not, it may take some trial and error to get it just right. It doesn't need to be exact but you just need to match the curve of the strip. Maybe I'll make a template and post it in the future. Iron it flat if you need to. Then fold the alcantara so the wrong side is facing you. Stitch close to the edge of the seam on a sewing machine. Make sure to backstitch your start and stop points. Then turn it inside out so the alcantara is facing outwards. Slip it on and reassemble. The knob has a small groove in the back for the seam. Good luck