Resetting connect premium
 

Recently tried updating the maps on my sat nav using the disks being passed round the users on the UK forum.

Long story short I misread the first step and tried updating the maps before updating the software first. Now the only thing I can use is the audio on the connect premium as restarting the update process doesn't work and I can't access the settings, sat nav or anything else :( any ideas??

Sub'd to see if anybody has an answer.

I'd try disconnecting all power to the nav unit (might be easier to pull the main battery terminal), waiting a few hours for any capacitors to discharge (or short each power lead to ground through a ~10 Megohm resistor), then re-connecting power. This should erase all volatile RAM.
But I wouldn't have high hopes of it working.