Welcome back to Beoworld Faisal,
I will take your last point first, the AVANT US type # 8490 user guide is on the B&O main web site. You need to log into "Community" to get to the downloads, so just register and you will have the user guide.
The following is the connections panel of an AVANT US model

You can use the DVD input to connect your DVD player and you will need to check if your DVD player is supported by the STB controller. Also, if you don't have one you will need a "IR" transmitter which plugs into one of the two "CTRL" sockets and the transmitter itself is stuck on the front of the IR receiver of the DVD player.