This really is a do it your self project since the final dish isn't approved by DirecTV.
In your case this is how I would proceed,Acquire the phase III dish and the Slimline3 LNB,Put the SL3 LNB on the phase III dish and replace your current dish with the new one,Align your new dish for the highest 101 signals to get your R22 unit back operating with the new dish.
After getting your R22 back in operation go and visit a DirecTV retailer (have your account # with you) order the equipment you need and have them upgrade your account to HD, Have them hook up the unit at the store and activate it. Tell them your going to put it in a Recreational Vehicle with a slimline 3.
Bring the unit home,do the guided setup for a slimline3 then tweak 99 & 103 © fourteen transponders for the highest signal numbers.
If you have questions post them here,I'm sure we can get you through this OK,What kind of dish do you have now the 18 inch round or the phase III??
You might just call a DirecTV dealer and ask for a slimline3/HD upgrade,you will get what you need that way,since your already a DirecTV customer this upgrade will cost you.
Edited by Matt9876, 31 August 2009 - 10:36 AM.