You can also call or email Winnebago Customer Services and they'll guide you on how to remove the old set.
I'm not so sure running a HD DVR through your switch box will be straight forward. For full functionality, I think DVRs require either two RG6 coax leads from the dish, or a SWM arrangement which I don't think all RV HD dishes support. In a 2001 coach, you might also have RG59 coax which might need to be upgraded.
Best of luck
Rick, Nancy, Peanut & Lola our Westie Dogs & Bailey the Sheltie.
2007 Itasca Ellipse 40FD