If I have a dish 500 right now with DP lnbs can I just change those lnbs to a set of dpp lnbs and be able to feed a dual tuner receiver? If is that easy with no additional aiming of the dish?
Yes, whether you have DP LNBs (rare) or the DP Twin, you can swap out for a DPP Twin and not have to re-aim. The LNBs aren't DPP, it's the switch in the DPP Twin that lets you connect a dual tuner with a single cable run and the DPP Separator.