Well Wharfdale don't make TV's, so it's actually a cheap Vestel set - and as far as I'm aware you can simply unplug the DVD player, and the TV works perfectly fine without it.
If you google for Vestel and the number off the main board inside (ignore any Wharfdale numbers) you should be able to find the service manual for it.
However, the fault doesn't sound like a problem with the DVD, more like a fault in the TV or remote, which is manually switching the TV to the DVD input.
As far as I recall, you can unplug the buttons on the set?, which might also unplug the remote sensor - so try that and see what happens. Some sets even have touch buttons, and these are nororious for causing problems.