I have a Mitsubishi HD 1080 Series TV. How to Make HD?

I have a HD 1080 SERIES. But I could never figure out how to make play in 1080i. So I get this crappy 480 signal. I have a ViP622 HD DVR from Dish Network so I wanna get a HD signal from it. Only thing is that it doesn't have HDMI port so how can the componet ports on it give me 1080? I bought this Tv a while ago when the word HD was brand new so it might bea little outdated. It is a Mitsubishi Rear Projection HD 1080 Series. About 60"