So that is a canvas type awning that has had previous lettering painted over?
It looks as if the paint is peeling off, is this the case?
If it is peeling all loose paint has to come off or new paint will not stick.
If you decide to power wash the old loose paint off, do so at your own peril, A power washer can and will cut through old sun degraded canvas or sunbrella fabric like butter, don't ask how I know!
It's always tough doing a half a$$ed patch job that should really be taken down and replaced.
Good luck.