Definately have your trailer on your truck hitch, DO NOT rely on the front jacks to support your trailer during this procedure as you will lose hydraulic pressure when you disconnect those lines.
Carefully disconnect your lines, DO NOT operate anything hydraulic with those lines disconnected! Get your battery in the compartment and reconnect the hydraulic lines. The fluid loss should be minimal, make sure to check your reservoir for proper level. Be prepared to add more fluid if necessary.
This last summer our fluid level fell below the recommended level causing the front jacks to "drift" down with the trailer leveled, I was instructed by Lippert to check the fluid level, if low (which it was), add fluid and run the slides in and out a few times along with the leveling rams to work the air out as we had gotten air into the system. Worked great, no more troubles. You may or may not have to do this but by running the rams in and out a few times you should be good to go. Good luck. :W
Dan
