Disconnect all the electrical power. Don't run the generator. Carefully get on the roof of the RV.
Find the location of the solar panel considering easy access for the wiring. Face the solar panel so the width is facing forward.
Drill holes where mounting screws will go. Seal the holes before mounting panel screws with silicone-based sealant. Feed the wires down the refrigerator vents.
Return to the inside the RV and find a good spot for the regulator panel. Usually it is put above the refrigerator. Cut an opening for a regulator. Fish the two sets of wires out through the refrigerator vent.
Connect the wires to the regulator panel. Make sure the appropriate colors match and the polarity is connected correctly. Use the most direct route to connect the wiring for the battery.