If he's on Green, then he does indeed need to push the Meditate button until level 35, at which point meditation happens merely by sitting. It's my understanding there should be a /meditate command, but it has not been implemented here.
This question has been asked and answered before in such threads as:
No meditate button
No meditate
Meditate
Question on Meditate on Green
Meditate Button is Solid Black
You pretty much always wanna do a few searches on these forums for any issues you may have.