You can see the procedure of adding it in the pictures attached.
I guess people have been building them in for a while now, in 7000 too.
But according to some news there will be a dvd kit for dm7020 on the market soon.
View attachment 1861
Dreambox DM 70XX DVD KIT no links to commercial sites nkl. MwSt.
zzgl. xxxx 79,00 €DreamBox 70XX DVD KIT für alle DreamBoxen der 7000 reihe.