As above, dead easy.
Open the door, on the inside of the door, at the end of the strip, there will be a small black grommet, take this away as some strips are held in place with a screw, T-20 i think.
Once the screw is gone, slide the strip towards the back of the car. The clips can be pretty stiff, on mine it felt like it was never going to come off.
I found it best to slide it as much as possible and then try and grip it at the end and pull it back from the car. Careful not to nip your fingers though!