As far as draining a full tank...that does suck, but you're just going to want to get as many clean buckets as you can--make sure you have enough before you start--and wait it out. Make sure to remove the fuel filler cap while it drains so that the liquid does not create a negative pressure behind it as it leaves (in other words, so it drains faster).

The tank itself may require extensive cleaning to get rid of algae, meaning removal from the vehicle and taking it to a shop. Or you could just try using algaecide in your fuel, but you may still get future clogging in your strainer from the remnants.

Good luck.

__________________
"I would rather be ashes than dust!
I would rather that my spark should burn out in a brillaint blaze
than it should be stifled by dryrot.
I would rather be a superb meteor,
every atom of me in magnificent glow,
than a sleepy and permanent planet.
The proper function of man is to live, not to exist.
I shall not waste my days in trying to prolong them.
I shall use my time."

-Jack London 1876-1916

1983 300CDT (running WVO since 12/05)
1981 300SD (parts car)