The original installation documentation is here. I strongly recommend reading through it in order to understand where the DETER install process is evolving from:
Since I have generated these images, I have added a few more packages to the meta package for the deter install and bumped the revision. Once you create a bootstrap user and have the repository cloned onto the image, updating should be painless:
cd testbed/install/ports sudo make install cd /usr/ports/misc/instant-deter sudo make deinstall sudo make reinstall
Create a build user of your choice on boss and users. If you are unfamiliar with FreeBSD, the process for creating users is laid out in the FreeBSD handbook.
Login as this user and clone the testbed repository:
su -l <builduser> git clone tardis.deterlab.net:/var/local/git/testbed
Create the object tree directory.
mkdir ~<builduser>/obj
Now go into the ~<builduser>/obj directory.
../testbed/configure --with-TBDEFS=/home/jjh/testbed/defs-<your defs>
This will create the object tree for the testbed.