The two compute nodes are relatively uncomplicated, as their primary filesystem is served over the network in a redundant fashion from the two masters. As such, their installation is relatively simple.
After physical installation, plug four 1G network connections into the first four network ports, and then into the first four ports on either Switch 2 or 3, as necessary. The exact order of these connections does not matter, just that the correct 4 ports are used on both ends.
Next, create a PXE boot USB stick. This can be done with a USB stick of larger than 128Mb that allows you to write to it on the block level, using, for example, dd or UNetBootin. Write the provided iso file onto the USB stick. You will need one per compute node. Insert these PXE boot USB sticks into any USB socket on the compute machines.
Now, Get the MAC address of the first port on each compute node, and update the database to include these values into the compute A and compute B serial number values. Compute A should be the one connected to Switch 2, and Compute B the one connected to Switch 3.
Lastly, boot the machines. They should automatically get their filesystem and begin processing.