When your tenant orders make sure you set him up as a referral for the $50 credit. Have him let the sales guy know that there is a dish there and you may need a bigger multiswitch to be able to share it.
Trace your lines from the dish and find a box that the 2 dishes go into, if there are unused outputs he could use those, if there are not enough you may need a bigger switch.
you should have one of these
DirecTV will supply the needed one, if you have a WB68 and are using all 8 outputs you will need the WB616 which may be an extra charge or can be bought on ebay or the sites sponsors.