On my 300D, I removed the little bracket that holds the brake booster vacuum line first. It is held in my two small bolts.

Then I moved the vacuum line out of the way before lifting the fuel filter out of the way. I spilled a lot of fuel. Next time I will suction some of the fuel out of the filter first to reduce spillage.

Set the filter in position empty. Then use a small funnel to pour fuel (I used kerosene) into the filter before tightening.

__________________
1993 W124 300D 2.5L Turbo, OM602.962
2000 Chevrolet Cavalier, 2.4L DOHC
2002 Ford Explorer, 4.0L SOHC
2005 Toyota Prius, 1.5L

http://www.fuelly.com/sig-us/40601.png