Upgrade to vCenter 5.1 Update 1?

hi guys

I want to upgrade to vCenter Appliance 5.1 U1, checking the vmware site to get the download I see this

VMware-vCenter-Server-Appliance-5.1.0.10000-1065184-updaterepo.iso

Comment says:

VMware vCenter Server 5.1.0 Update 1 Appliance

Use this package to update from VMware vCenter Server Appliance 5.1.0a, 5.1.0b to VMware vCenter Server 5.1.0 Update 1 Appliance.

Right now I have multiple vCenters 2 different builds

VCPAM  - Version 5.1 build 880146 - vCenter Server Appliance 5.1.0a

VCDOMC - Version 5.1 build 799731 - vCenter Server Appliance 5.1GA

VCDCRR - Version 5.1 build 799731 - vCenter Server Appliance 5.1GA

So what is the way to upgade from 5.1 GA release then?

for what I see I can upgrade my VCPAM but what about the 5.1 GA releases vCenter appliances.

thanks