On the C230 I believe there's 5 hoses.
The DVD manual recommends using clamps on the hoses.
I just swapped out the old fuel filter for a new one today. M111 filter is located in the exact same spot, and is the same filter pictured above. There is only four hoses, not five. I would also recommend using clamps, but definitely not the OEM clamps on there. Get some of the screw type adjustable clamps.
For me, I didn't completely pull the old filter,
IMHO it's better to do one or 2 at a time so you don't get confused as to placement, and you can clamp them off to avoid spillage.
You can buy special little hose clamps at most auto parts stores that
sell tools, but I used vise grips (not too tight) and some other clamps I found in the bargain tool bin.
Before the filter change I ran the tank down to 1/4 full, and didn't have any problems with leakage. Just the fuel already present in the lines, but for the most part it's the filter that leaks a lot. The lines stay in place, so it's not to hard to mix it up, but definitely make sure you get it right...
Before starting the car, I turned the key to the 2nd position,
let the fuel pump kick in, and waited for a minutes to let it pressurize.
Not sure if this helps or not, but I didn't get an CEL's and others have.
Good tip. I knew the oil filter has this feature, but didn't know about fuel pump.
It was nearly dark when I had just finished getting all the clamps tightened down, so I haven't started vehicle yet. Have to figure out how to get that holding clip back onto the filter tomorrow...