It's not something you can do with the wheels on the ground due to clearance/access. As long as the wheels are both at the same level, say on ramps then there is no "load" on the ARB. Use fairy liquid or the like to lubricate the bar & links as they are a PITA to get on the bar ends, WD40 or the like is no good, it needs to be "soapy"
Why are you changing them? I ask as I'd only d it if one had snapped, other than that, they are good for 150k plus, as there is nothing really to wear in them.
Mike