This is actually quite a simple procedure and doesnt take too much tinkering. Here is how I achieved the following set up ;
1 - Firstly you need a Universal Modulator. These are available from Maplin for about £30 however you can buy cheaper ones on ebay for around £10
2 - Connect your DVD player via the scart socket or RGB cables.
3 - Connect the RF Output to the TV (For this set up I also required an RF big-to-small adapter)
4 - Tune Your TV to channel 21
Note - The Maplin universal modulator converts stereo sound inputs to mono.