Come on then...how easy/hard is it?

I've wanted to try water cooling but never had the guts, always believe that i will start the PC up and see liquid gushing out of the PC lol

What would you guys recommend? Here is my system details:

AMD Phenom II 940 3Ghz
4GB DDR2 Corsair Dominator
MSI DKA790GX Platinum
2 x 160Gb WD Raptor 10k - Raid 0
Ati Radeon HD 4870x2
Corsair 750watt
X-Fi - Fatal1ty Series PCI
Antec Nine Hundred Case

Basically i want to get rid of the cooler on the CPU (can't remember the name but it's quite big!!) and maybe look at cooling the GPU with liquid.

I believe i will need to change the case but not too bothered about that (don't tell the mrs!!!)