Upgrade best practice to 2012 SP3

Dear All,

We currently use Backupe Exec 2010 R3 SP3 on a Windows 2008 R2 media server. We are also using Vsphere 5.1.

I read for support of Vsphere 5.5 we need to upgrade to 2012 SP3. In a prior thread I read that we need first to upgrade BES before upgrading Vsphere to 5.5

Are there some guidelines availble  how to upgrade BES on the same media server from 2010 R3 SP to 2012 SP3? 

Thanks,

Edy