ginja_ninja wrote:I've pushed and pulled and prodded and twisted forwards and backwards... and not much happens - it just spins and spins.
I did manage to get it off once, but then after putting it back on, its stubbornly refusing to budge now.
If it's just spinning and spinning, it's probably locked.
Ours (new cap) is a real PITA to remove - unlocked, you need to grip it HARD and sort of push/twist. I tend to find the easiest way is to go as hard/far as you can, then pause and stare at it for a few seconds. That gives it time to have a little chuckle to itself, then decide to allow you to unfasten it more easily.
If you really can't get it off, then unscrew the whole housing from the side of the van, and you can undo the filler hose from the back. Then you can figure it out at luxury in front of the tv, or just bin it and replace with a whole new one if it REALLY pees you off...
Also any suggestions on what to clean/sterilise the tank wink?
There's umpteen proprietary products out there - have a look at any campervan/motorhome/camping/outdoors site. TBH, we just haven't bothered. Rinsed it through a few times, then just filled it and refilled it and kept on filling it. We don't drink it raw, though. Bottled for drinking/toothbrushing. Boiled, no problem. And we've filled in some potentially dodgy places.
You can get into the top of the tank through the bottom of the downloader cupboards. There's a cover plate. Unscrew that, and you're into the top of the tank, where there's a big plug. It's all fairly obvious.
And finally - how do you empty the fresh water tank (short of running the tap for ages!)?
Look underneath, just in front of the kitchen side rear wheel. There's a plastic screwcap over a stub of pipe. Undo that. DO NOT OVERTIGHTEN IT - it WILL break. Mine's about 50% structural superglue.
**Newbie alert!** 
