To make a structural repair, I would suggest using our Carbon Fibre Rapid Repair Kit.
This includes some carbon fibre fabric and epoxy resin so that you canadd some strength from the inside of the part. You can add layers underneathwhere it has worn away.
You will need a sharp stanley blade to trim away the yellow kevlar"fluff" you can see in the photo. Also during your preparation, tryand remove what looks like marker pen or black paint someone has used to tryand disguise the damage as it makes it look worse. You can also ‘run’ someresin into and around the cracked carbon fibres on the surface which will sealthem and so water ingress or further damage on the surface.
Having added some new, additional reinforcement on the inside of thepart (restoring its strength) you can apply a layer of resin across the surfaceof the repair and then sand and flat this down to make leave a smoother finishto the repaired area. The release film in the kit is quite useful forstretching over the curved surface to give you a relatively smooth finish tostart with and thus less sanding work. Finally, as the part was glossyoriginally, a coat of 2k PU lacquer over the whole part will bring the fullgloss back and leave it looking as good as it can.