The rear seats are bolted into the pre 2008 version ie the original and its 'facelift' successor. In the post 2008 model they're removable in, i think, all versions. Certainly rthe are in my wife's 2013 XTR model.

I presume therefore the OP has the earlier model.

My first thought would be why bother? You gain loadspace equal to that occupied by the folded seats but tbh it's not a lot - alot less than foot. Camping with a four amn rigidome tent and a lot of kit we'd easily get it all in with seats in place. Even if your 'camping' is to sleep in the back off the car I'd say it's hardly worthwhile. You'd obviously lose the flexibility to carry any rear passengers while on your trip.

The handbook for my 05 version contains no instruction for unbolting the seats though it's pretty obvious how you'd go about it. I don't think there's any hard/fast answer for the OP. My advice would be to tell them you intend to use it from time to time with seats removed and see how they react.

TBH, as long as you dont carry 'loose' passengers in the loadbay it's difficult to see any harm except that the folded seat is a substantial barrier to any luggage thrown forward in a sharp stop.