Tear duct tape into strips about 3/4" wide and apply a couple of layers of it to the paint just inboard of the sealer you want to renew. Then use a small-diameter wire wheel in a variable-speed drill motor to clean the area prior to applying the new stuff. I don't think it's a good idea to leave any old sealer- - - -you'll just trap contaminants where they can cause problems down the road sometime in the future.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!