Chances are, if the graphics are bad, then the gelcoat is oxidized, which means it will need to be buffed out and then polished to a shine.
First thing to do is remove the graphics. If you're going to replace the vinyl with the same design, then you won't have to worry about any shadowing left behind and here's why... when vinyl gets weathered from the sun, it shrinks first before it becomes an eye soar. With that in mind, you first need to strip the graphics using a heat gun and some plastic razor blades. It is actually better to strip the graphics in the direct sun as the heat from the sun helps soften the vinyl. Re-applying the graphics is done by simply lining the new graphics up to the shadow left behind by the old graphics.
When you receive the new graphics, they should be sandwiched between a top layer of transfer tape (better recognized as masking tape) and a under layer of paper that is peeled back revealing the sticky side. There are several youtube videos that demonstrate how to apply graphics, it's simpler that you think.
Once the graphics are off you can wash the RV using a dawn dish detergent and LA Awesome mix. This will strip most of the oxidation and left over wax off the RV. Do not use this mixture on the roof - this is for the sides only. Chances are, you have either a EPDM rubber roof(ethylene propylene diene Monomer (M-class) rubber) or a TPO Rubber (Thermoplastic Polyolefin) roof. It is advised not to use anything that contains petroleum distillates and citric ingredients when washing a rubber roof. These chemicals will damage your roof membrane and shorten its life.
Once this is done tour RV is ready for detailing. To protect your new graphics from future weathering, apply some 303 Aerospace over the graphics every 3 to 6 months and they should last a lot longer. Good Luck
