Well, you could put it on radial decouplers on your lander fuel tanks (either taking a spare rover, or figuring out the correct counterweight) - or you could give it its own decent engine and parachutes (skycrane), and attach it to the top, and then land it before the lander. or you could land it on top of your ship, and then use a couple sepratrons and a parachute and blow it off the top - but your probably need to strut the crap out of it for a safe landing.