Are there any gauges or scrapes on the spokes and do you require a mirror finish ?
If no gauging you need to sand back the lacquer. I'd start with 800 wet n dry maybe something a little coarser to get the lacquer off . Then a 1200 , 1500 and finish off with 2000 wet n dry and a final polish with Mothers alloy polish. You will end up with mirror finish spokes . I'd put aside maybe 5 hours a wheel depending on elbow grease applied.
If the spokes have a machined finish you will need a lot coarser paper to get rid of that before wet n dry ..