Agree with Ed, MEK will dissolve Red Kote
. Also agree with Eugene. I have had 2 tanks done and friends have had a couple done and Red Kote is great stuff. Course, I have it done professionally and that way I don't have to deal with the smell or the compounds and I don't have to worry about a mess. Red Kote can be applied by folks like us provided we follow the manufacturers directions.
If you must to it yourself, I would clean the tank with MEK .. then once the tank is properly clean - reapply according to the directions.