Never done ones on the Freelander but the ones I once did on a BMW. meant removing the pistons first, cleaning up the edge of the caliper where the seal/gaiter fits, install the gaiter then gently put the piston back in making sure the gaiter doesn't come adrift. Removing the caliper off the car is easy though. Might be worth fitting new inner seals as well if you have to do the same with the Landy.