Paul,

Take a look here: http://biodieselbob.blogspot.com/2008_07_01_archive.html
Read the 4th of July entry.

You have to drain the tank first. Then remove the hose that leads to the strainer. Remove the rubber covering---should be able to remove with your hands. To remove the strainer, I made a 46mm strainer removal out of angle brackets I had lying around and a piece of steel. I then welded on two nuts that was threaded on a bolt. It worked amazingly enough. Wanna borrow it?

I recall it was a bear getting it off. it almost felt like I was going to strip threads. But one good push w/ a cheater bar and the strainer came off.