Sure, but althou I've tried to change back and forth "ssh access for admin" from bash to disabled to the other one, I had no success.
Since I only wanted to su - admin, I've managed to change the line with the admin user from /etc/passwd and replaced /sbin/nologin to /bin/bash
Still can't ssh login, but good enough that I can switch from root to admin.
Thought it was safer to let admin ssh login instead of root.... this needs a polishing touch