[CentOS] Re-booting into CentOS-7.2 - advice sought

I have a remote home server updated to CentOS-7.2.1511
(as stated in /etc/redhat-release)
but I have not re-booted since the update.
The machine is currently running kernel 3.10.0-229.11.1.el7.x86_64.

I'm wondering if anyone has advice on any safety steps I can take
before re-booting, so that in the event of failure 
I can give simple instructions to my daughter at the other end
on how to get the system running?

Any suggestions gratefully received.


-- 
Timothy Murphy  
gayleard /at/ eircom.net
School of Mathematics, Trinity College, Dublin