There is no direct migration path from UCCX to UCCE (the newer names for eXpress and Enterprise). The platforms are completely different. The UCCX servers could be reused as IP-IVR servers depending on their specification, but a licence would be required for that.
The ATP is an (someone correct me if I go wrong) invite only program for specialised Cisco Advanced Technologies (of which UCCE is one). To perform a migration / installation you either have to be an ATP or work with an ATP in your region.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...