Getting rid of it might take a year or two. I'd spray now with a summer, light weight, oil and something like Bayer Once and Done. That won't kill all now but maybe some. Then next winter spray at least once with dormant oil. You need to keep an eye out after that and always spray dormant oil.

You can search Google as well as I for more information.

malathion, carbaryl, permethrin or esfenvalerate will kill crawlers when crawling not under scale all spray are to be heavy up to run off. using oil best in winter. There 3 generations now to September. They came to your peach tree form other plants in your area need spray as for from your peach tree as can other trees. You mix mix permethrin in latex paint use interior clear latex paint.

Can you give me more info on the permethrin and latex paint. I could not find much on google

Florida has detailed spray recommendations.

Here is a link that might be useful: white peach scale control