Renewing Without Sea Time?

I was directed to this website by one of my classmates who said I could get my questions answered here:

I’m active duty Army and graduated from a maritime academy in 2011. Since graduating I haven’t used my license (3/M, Radar/ECDIS) but would obviously like to keep it in case I I sail one day. I just renewed my TWIC, but see there are some new requirements since graduating ie: OICNW, CG physical etc.

My questions are:
-What do I need to do in order to renew my license without sea time and keep it current?
-Which trainings should I attend?
-Can I renew the license within a year of it expiring?

Many thanks!