clearing up details on coolant change 87 300E

[dirtysocks]

Okay, I am going to change out the coolant in my 300e. It is the same coolant that has been in it since my dad bought it about 3 years ago. It is a funny brownish green color. I don't know what kind it is. I want to get as much of it out as possible, to prevent possible reactions with the new coolant (Zerex G-05). I know where the drain is on the bottom of the passenger side of the radiator. I don't know exactly where the drain is on the block.
Can anyone tell me where to look for this drain?
Are these the only two drains for coolant?
To flush with regular water, should I just close the drains, fill up through the resevoir tank, run for a bit, then drain again?
Is that all there is to it?
Will a simple water flush be sufficient to expel the old coolant?
Any other tips or quirks I should know before doing this?

Thanks for your time.

p.s. Did a search already, and all the threads seem to break down to an argument over which coolant is best, with little info on actually performing a fluid change. If someone can provide a link to a thread which has already answered my questions, it would be just as good. Thanks.