whatever you do dont try it yourself you'll go through the laquer , the best thing you can do is to get them re diamond turned we offer this for £75 +vat per wheel this process with us takes 5 working day and come back like new we are forever doing monza 2's there prone for this .
its not pitting its water corrosion which appears after a while due to the alloy being porus or after being damaged and water gets underneath the laquer
hope this helps