How to change Windows Server 2012 password requirements when installing?
There are 5 phases of Windows installation, the second to last is Specialize. This is the phase right after you typically see "Detecting Hardware" and all of that fun stuff. You can run commands in an automated installation during this phase before any user accounts are created. You would script the import a local security policy using
secpol.exe that has your modified requirements. Then, by the time the OOBE phase happens (which is where you create user accounts) you should be good to go with your custom policy.
To do something like this you need to be doing an unattended installation, but I'd assume if you're asking this it's because you need to do this on a large number of servers, otherwise you'd just set a temporary password for the 2 minutes it takes to log in and change this setting.