How do we set APT priority for Debian 12 - Bookworm

Well, its official, Debian Bookworm is now the Debian Stable branch. 
Their web site does not seem to have caught up with this, but you can install the XFCE ISO from here
cdimage.debian.org/debian-cd/current-live/amd64/iso-hybrid/

But the version of Linuxcnc in it is a few months old and now there is a Buildbot that is building version 2.9 that is always current.
​​​​http://buildbot2.highlab.com/

It should be possible to set up our sources.list so this repository is checked before the official Debian repo but I don't know how to do that. I think it involves pinning and setting repo priorities somehow
Can someone help by providing a solution?
I can then include it in our getting Linuxcnc documents for Linuxcnc 2.9
​​​​​​

Worked it out: posted the solution here
forum.linuxcnc.org/9-installing-linuxcnc...t-on-debian-bookworm