I did a fuel filter change on my C -class for the first time last week, and learned some stuff.
When you buy the filter, if you do it at a dealer, take your vehicle vin number so they can see what type of connections are used to connect the hose to the filter.
My car used clamps, so I purchsed new clamps ( screw connnction ), however the old OEM clamps on the car needed to be cut off, they didn't screw tight but used some kind of interlocking snap. I used a utiliy scissors to snap the old clamp apart.
Some models use union nut and bolts with copper washers, copper washers for this type of filter have to be replaced.
I did disconnect the negative terminal from the battery, I also removed the fuel filter cap to relieve pressure.
The filter under the car is protected by a plastic shield, I needed a twleve inch extension to poke throught the access holes in the shield to reach the plastic nuts attaching the shield to the car.
Some filters use an insulation cover which can either be replaced or reused, and notice the direction arrow on the filter, so new filter arrow points in same direction.
The filter itself may be attached with it's own bracket, easy to loosen with a screw driver. The rubber fuel lines if attached by clamps need a little prying and twisting to get off. A catch bucket for spilled fuel and two hose clamps - small vise grips utilizing some kind of soft surface that touches the hoses - can be used to squeeze the hoses. actually not all that much force is needed to squeeze the hoses closed.
Need to be careful that any fuel spill is minimal and that tools are not banging about which can produce sparks. I doubt a fuel filter change can produce enough fumes to ignite - but be careful.
Everything goes back together easily, reconnect the battery, and when you start the car - expect a little extra crank as the fuel pressure builds up again.
Actually there is a little test you can do with the old filter, blow through the old filter in the opposite direction the filter arrow points ( don't put your mouth on the filter, maybe a little tap that won't ignite a spark ) and collect fuel and debris on a white surface. Check for any rust colored particles or anything to TRY to tell how much dirt was collected.