2 tonne jack is fine. Ideally hitch the caravan up for stability before jacking and chock the opposite wheel(s). I have always jacked on axle tube close to wheel.
2400kg!! that is a big c/van it must be a TA but a 200kg trolly jack should be ok just use axle tube of wheel you want to change but chock other wheel/s
I was not aware that Coachman built anything that heavy, even as a twin axle. At 2400kg it certainly wouldn't be a single axle as there just simply aren't any single axle caravan chassis on the market that take that weight.