Thanks for this...I've not managed to find time to get the lights out yet but will update when I do. Appreciate the advice not to drill the front!

Ooh....interesting idea....would you remove the light and drill the floor of it? Or leave it in and try making the hole on the front?

I have a lot of water in my headlights. One is almost a third full. My mechanic recommended I order some on ebay to replace them but I wondered if it was possible to drain them somehow and repair the seals? They seem very expensive for old headlights that may also have the same problem. Any ideas ...

I'm so grateful for this thread....it turns out our bongo also needs to have the blowers on to raise the roof! Thanks folks!