It shouldn't be too difficult to do. Trace the propane lines underneath your rig and find an appropriate place to either cut the line and put a tee in it or find a tee and make it into a cross. Then run the new propane line up and underneath the new stove.
You can do all of this with copper tubing and flare connections (or maybe RVs use compression fittings, but flares are much better). Make sure that all of your connections except the final one to the stove are below the floor where leaks won't be as disastrous.
David
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