I did the same job on my DS a couple of years ago. If you have a Freightliner chassis then our units are quite similar. I had determined in advance that the elec system would run ok without the batteries installed, and that's exactly how it worked out.
A summary of my job, with pics, is titled "Cleaning up a battery tray", in the "Quick links and Mods #3" of the Newmar Owners forum section.
John & Diane, fulltiming since '12 02 DS40, FL, Cat, '04 Element NHSO RVM103
John, Diane, and Lincoln, the guard cat. RVM103
Fulltimers since June 2012
2002 Dutch Star 40, Freightliner, Cat 3126, 2004 Element