Just did this job so I thought I would post. Did it from the outside by removing tire and taking wheel well out. After the tire is off you have 3 t25 torque screws and 4 10mm plastic nut to take off. Once they are off start to gently work the well down from the back forward. Not to difficult you just have to see where it hangs up. The studs where the 4 10 mm nuts and where it slides onto the metal fender around the outside circumference are the two main spots. Once out the hose is plainly visible in the front of the well. Hit it with compressed air and rinse.

 

I managed to remove the filter plate from the left front drain, and to clean the tube bij using compressed air, see pictures below.
To put back the plate is a little diffiicult, put it back with the flat side towards the inside of the car. I used the handgrip of a hammer to gently push it into its place along the sides in the rubber.

I made some pictures of the left rear drain location to show you how to remove drain plate.

This approche saves a lot of work (removing the wheel etc).

Cheers, Guido