clean them with alcohol and use high temp paint. If you use a rattle can you should remove them prior to painting (think over spray) brush is easier but doesn't look as good. It dpends on how much effort you want to do. I'll also suggest wax inside your rims when you have them off to aid in cleanup year round....good time to install wheel locks too.
2012 V6 traded for a 2017 VW GTI