Drop by almost any AutoZone, Discount Auto Parts, etc... look at the rack of "Haynes" or "Chilton's" auto repair manuals.
Find one with the shrink-wrap removed... there's always at least one dog-eared, grease-stained copy in the rack... Management knows it will keep the other ones safe.
Don't be terribly concerned with Ford/GM/Chrysler, etc. ...but IF Karma is with you and you DO find one that relates to your chasis... all the better.
At any rate, there will be an illustrated, step-by-step guide showing how to adjust the headlights.
It is pretty much the same across all makes.
May require a "Torx" type screwdriver. Buy it at that store as a token of your appreciation for the use of their "Resource Library" ...it's just the polite thing to do.
Armed with this knowledge... knock yourself out!
Final results should give you a good light pattern on the road on low beams WITHOUT offending oncoming cars. The high-beams will naturally follow the correct low beam adjustment because there is a "fixed" relationship within the bulb or sealed beam lamp.
IF you are getting a large number of "flash-ups" requesting you dim while on low beams... it is a fair indication that you need to re-adjust.
Also, bear in mind that a load on the rear... i.e. a trailer with excessive tongue weight MAY change the dynamics. Anticipate that and adjust accordingly.
Your heavy RV will be less prone to that problem than a passenger car or truck.
There will be a happy medium which will suffice without having to constantly adjust for changing loads.
Hope this helps you...
Jim and Fran in Central Florida
1989 Country Coach Sedona Mark V
Turbocharged Detroit Diesel 8.2L "Fuel Pincher"