a shop normally will use a fine grit cleaner and high speed buffer to remove them and sometimes cost a arm and leg..lol
Unless you have a hookup like some.
If you try it w/ thinners I would recommend diluting it a ltitle and as mentioned use a Q-Tip to apply the solution. Once you are finished I would wash and then wax that area. Hope this may help and good luck w/ what you do or did..