BMW X1 Series F20 F30 F35 Cooling Reservoir Radiator Supplemental Water Bottle for 118 318 320 Models Frey Brand N20 Model

I didn't take any pictures, just swapped it out directly. To avoid losing coolant, I first used a hose to draw out the coolant before changing it. It's best to replace the whole base too; you can easily pop off the two base clips with a flathead screwdriver. It's a bit simpler than just changing the jug, but be careful with the lower hose. After pushing the spring clip in, it's a good idea to pull the hose back and forth a bit to make sure the clip is fully seated, otherwise, there's a risk of the spring popping out and causing a leak.