Most good devops book tells you how to do that. You scan for people who have the right skills and who actually care, as opposed to people who are at the other end of the spectrum who think that if it ain't broken don't fix it and "why change it we will have to support this stuff later".

Then you go commando and secretly pick projects with low cost and high return that would not normally get the go ahead. People copying Excel sheets full time? Automatate their job away. Full time sysadmin setting up one server a day? Would be a real shame that you have a docker container ready to use when he has an emergency and doesn't have time. Bonus success points if you do things that also help your fellow devs.

In a government settings, and in any large organizations, you will need to have upper leadership support otherwise this will always fail and all of your efforts will be undermined and suppressed. Be sure to leave an employee review on your way out and name names to HR.