Get Wasso to polish it... simples
If you want do it yourself - make sure you have patience! I've done mine - took me a week!
Took it off, cleanned off all oil etc with something like brake cleaner etc.
Then went over with wire brush drill attachement to get rid off big lumps
Then fun begins.... sanding all down... going from something like 200 grit then 500 ->750->1000->1250->1500 (both wet and dry)
Then cutting compounder, polish and wax it to protect
really time consuming and messy! If you got some cash spare - I wouold deffo give Wasso a shout!