You can start by reviewing the compatibility information of latest CVP version with other apps in the mix, ICM, CUCM.
Then review hardware compatibility of each to see if your current hardware will support the new apps.
Then review upgrade guide for each app and plan your upgrade, this typically may need to be planed to be accomplished in couple of more phases as these are not trivial.
You also need to see if your CVP deployment is using H323 or SIP, is with new versions of CVP H.323 is no longer supported so you will need to convert your config to use SIP.
If you have never performed UCCE upgrade it may be overwhelming and you may want to seek assistance from authorized UCCE/CVP ATP partner.
HTH,
Chris