Challenged with Going from Integrated system to separates

Hello,

I have an audio /home theater that is all powered by a marantz 7015 and 4 external amps. In this scenario , I use marantz AV receiver as video processor , and preamp .  I have dedicated amps to power up my 7.2 channel.

i have recently decided to go separates and picked up McIntosh MCD12000 as the DAC and C12000 preamp which will feed into a McIntosh 1.2k  mono block AMPs for 2  channel audio . The c12000 preamp as bypass mode if I wanted to bypass a video processor for 2 channel audio.

Challenge /question:

how do I put the marantz AV receiver in this set up , so that I can use the marantz for home theater  processor ?