I know there are a few guides out there with how to do this but i really couldnt find one that helped. So im writing this in the hope it will help at least one person.
I will set it out in easy to follow steps as best I can.
Stage 1: Create the USMT Package and prepare System Role
Im not going to type this out again, im just going to point you to the excellent USMT package creation tutorial on the web site currently
Add System Role for State Migration Point
Click Administration > Servers and Site System Roles
Right Click on the server you wish to use
Add Site System Roles
Click next and put a tick in the State Migration Point.
Follow the wizard.
Stage 2: Collecting the information
The following stage assumes you have already deployed an operating system to the destination computer or the computer is new, on the domain and listed as a device in SCCM 2012.
Open SCCM 2012 Console
Open Assets and Compliance > User State Migration
Click on Create Computer Association in the ribbon along the top.
Under the Computer Association tab. Next to Source Computer box Click Search, Click Search again. Use the filter to narrow down to the computer you will use as the source. Click on the Computer and click ok.
Repeat step 4 for the destination computer.
Click on User Accounts Tab along the top. The Migration Behavior should be self explantory. If you wish to transfer just specific user accounts (default) click on the yellow star underneath this drop down to select from Active Directory which users you which to capture from this computer.
Your association is now complete.
Stage 3: Isolate the Computers
Click on Assets and Compliance > Devices
Find the source computer
Right click on the computer > Add Selected Items > To New Collection
When the wizard for a new collection appears. Call the collection Capture User Data (or something similar)
Click next all the way through the rest of the wizard.
Repeat the above steps for the Destination computer but call the collection Restore User Data
Stage 4: Create the capture Task Sequence
Click on Software Library
Click on Task Sequences
Click Create Task Sequence along the top
Create a new custom sequence > Next
Call it Capture Task Sequence or something similar
Click next to everything
Right Click on Capture Task Sequence and click Edit
Along the top click Add > User State > Request State Store
Make sure Capture state from computer is selected and put a tick in If Computer Account fails..
Click Add > User State > Capture User State
Browse and select USMT 4 for the package. Capture all user profiles using standard options. Enable verbose logging & Skip files should be checked. Capture using VSS option selected
In options tab Check continue on error.
Click Add > User State > Release State Store
Deploy this to the Capture User Data collection you created earlier.
Stage 5: Create the restore Task Sequence
Click Create Task Sequence again
Create a new custom sequence > next
Call it Restore Task Sequence or something similar
Click next to everything and click finish
Right click on Restore Task Sequence and click edit
Add > User State > Request State Store
make sure Restore from comuter is selected and put a tick in If Computer Account fails
Click Add > User State > Restore User State
Browse and select USMT 4 for the package. Restore all user profiles. Check Continue if some files cannot be restore and enable verbose logging.
Add > User State > Release State Store
Deploy this to the Restore User Data collection you created earlier
Stage 6: Capture the Source Machine
On the source machine, open System Center 2012 Software Center. If the task sequence isnt there yet, leave it for a few minutes and press F5 to refresh. If it is there, click on it and click Install. A warning asking if your sure you want to install and operating system. Just ok this as your not really installing an operating system
Leave it to do its stuff.
Once its finished we're on to Stage 7: Restore to Destination Computer
On the destination computer, Open software Center as above and look for the restore task sequence. When it appears, Install and click ok the message about an operating system
Leave it to do its stuff
Hopefully, your data should now be on the new machine.