Hi Mike - I'm new to this stuff, but I managed to download the preset and the user cabs from the links in the original post.
I then used Axe Edit to import the preset into a blank preset (424 for me) from my downloads folder and save it. I then selected the cab from grid view in Axe Edit and clicked on the 'picker' option in the cabs section for Cab 1 (which is set to User). That should open a list of user Cabs.
You will need to import the new user cabs (that you will have downloaded from the link above) by clicking the 'manage' button at the bottom right. Once the manage window opens click user slot 7 and right click and select import. Browse to your downloads folder or wherever you saved the files from the link above and select the file 'U1-0007_TV GB 57 C TR.syx' and save it. Follow the same process for User slot 8 with the other cab file. The only other change I had to make was to change the Output block from 'Output 4' to 'Output 1' and it worked and sounded great for me (thanks Leon).
As I say I'm new to this but I managed to fumble my way through as described above, so the hopefully the description helps you.
If not I'm sure a more experienced user than me will be able to help. In fact there is probably a video somewhere on how to do it properly that someone could provide a link to (hopefully).
Good luck and fingers crossed it helps.
Cheers.