You don't have to get all the wheels totally off the ground, but you DO need to offload all of them. There's not a whole lot of suspension travel on these things and I've done the following over ten times now:
From level position, let the front down until the back stabilizers are off the ground about three to four inches. Put jack stands under the rear near the stabilizers with cribbing if needed. Raise the front to slightly nose up and put jack stands under the frame towards the front. This will still have the tires touching the ground, but with little weight on them. I use an auto floor jack to lift each wheel & put a jack stand under if needed.
This is how I've installed wet bolts, changed all four tires (took them to a place that couldn't jack the Monty), and replaced all the brake assemblies. I only do one wheel at a time if I'm repacking (I follow the EZ-Lube directions). Just reverse the process to get it down. If you've Level-Up, you good to go.
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