Upgrade Opscenter from 7.6.0.3 to 7.6.1

Hi

Current environment:

Master server running on Redhat Linux 6 with NBU version 7.6.0.3

Opscenter running on Windows 2008 server with opscenter version 7.6.0.3
 

We have totally over 7 Master server in our environment with either 7.6.0.1 or 7.6.0.3 version on the NBU side.

We are going to upgrade the Master server to 7.6.1, and in order to do so, we have to upgrade the Opscenter first.
I have read the opscenter admin guide and the upgrade section and I have some questions regarding the Opscenter upgrade:

1. I read somewhere in the opscenter admin guide that data collection on the opscenter needs to be disabled prior to upgrade. However it does not mention that during the step by step procedure for upgrade in the admin guide. Am i suppose to disable the data collection for all the master servrers from the opscenter or not?
2. It is mentioned about the AT and how that has changed in 7.6.1 version. Depending on the upgrade scenario, one might need to perform some steps prior to the upgrade. Wheter or not to perform these steps is based on wheter we have cluster\non cluster environment and wheter AT is share or remote. My question is how do i figure if my AT is shared or remote

Any other suggestions are appreciated.Thanks