Try to get at the chip with some 400 to feather it out smooth, then hit the rest with a grey scutchbright pad. (dry or wet) Though I like scuffing wet with soap water.......cleans and scuffs at the same time
After cleaning it with wax/grease cleaner
spray one wet coat of sealer (epoxy sealer is fine)
followed by your paint after flash time.
Don't use the green scutchbirght bads.....they are too harsh