Newbie - drain radiator Def90

Hi
Sorry if this is a klutz Q but I have just got Defender 90, 200Tdi. Today I managed to successfully do complete change engine oil and filter and planned to drain cooling system so I know age and strength of anti-freeze.
I cannot work out how to drain the radiator!
Looking from the top towards the engine compartment there is a low radiator pipe with a screw clip hard in to cowling on my left hand side. I think this is pipe to ease off but cannot get a screwdrive onto it so worried it might be the wrong pipe. There is also a pipe on the other side of the radiator - from what I think is the turbocharge radiator - but it looks more accessible from below. Don't fancy a faceful of cooling liquid when I get it off though!
Any tips on whether the left hand pipe is the right one and whether I need to get a 14" screwdriver to get it off?
Any help greatly appreciated.
Thanks

Malcy

Undo the pipe at the bottom that comes from the engine and pull it off the rad, out comes water from engine, out comes water from rad.

Also worth taking the top one off, so you can flush the rad and engine with a hose.

Thanks I will try that.
From what I can see that is the left hand pipe on the radiator as I look at it with the nut that needs a 14" screwdriver. Do all you guys have such screwdrivers as standard or is there another way?
Best wishes

Malcy