Once you are en E-5, you put in a package (request) to go into recruiting duty. They generally solicit for volunteers once or twice per year. There is some paperwork to be done, and an interview process. If you get through that part, you then have to be released from your rating by your assignment officer. If you get through that, you get orders to a recruiting office. That's it in a nutshell.
I don't recommend this job for someone with less than 10 years in though. The reason for that is that because you are removed from your rating, you would have a hard time learning everything you need to learn in order to advance in your rating. If you do it too early in your career, you could miss out on valuable learning that could slow down your advancement (promotion) process.
PO1 Kevin Couture