draining

I have just assembled my first custom loop, and after running the Blitz cleaner though it i have found its a pig to drain in its current config, any opinions from more skilled people on how I could change the config to make it easier to drain would be appreciated. Thanks.

I had a custom water cooling system built by overclockers 2 years ago and I know you're supposed to drain your system every so many months. The problem I am having is they didn't put a Drain fitting on so I have no idea on how to drain my system without causing major damage by spillage or...