Are you trying to use multiboot?
You first stated that you wanted to update your channels, now I'm not sure what you're trying to do.
I can tell you that Blackhole is an image for VU+ receivers, not Dreambox receivers, as it's based on the official VU+ image.
There was a version, of Blackhole, for Dreamboxes, but it's nothing like the genuine Blackhole image.
Dreamboxedit is a program, that runs on your PC, and connects to your Dreambox via the network.
Can you please provide more detailed information, regarding whay you're trying to do, and the problems you're facing.