Right, this is very early days and what I've done might not work fully.
I chucked the disc in a PC and booted Linux.
The disc contains 3 partitions. All are marked as ext2 format, but the second one is infact swap.
The 3rd partition contains the .trp files which make up the recordings. Guides for converting these into something useful can be found elsewhere.
The 1st partition contains a number of directories:
/inview
/inviewepg
/inviewloc
/library
/message
/schedule
The 'messages' you receive can be found in the /message directory encoded as single frame mpegs.
In the /inview directory is a file called 'script' which is an odd tagged format that I havn't quite fully decoded yet, but it contains an entry for each channel in the TUTV bar with information about how much disk it takes up, LCN and pointers to files in the /inview/usr directory for the icons to be used. At the end, it has references to the advert images that get displayed on the top bar these are also found in the /inview/usr directory.
What I've done is chopped the script file short after the inital tags which dictate EPG Session start time and end time, and then changed the permissions on the file so the 'script' file shouldn't be overwritten when then new batch of advert images are downloaded.
Hopefully, this will allow the 14 day EPG update to happen, but still get rid of the adverts and TUTV bar.