1. Purchase the correct air filter. The air filter for a BMW R1200RT is a cylindrical foam filter. You can purchase a replacement filter from a BMW dealership or online retailer.
2. Remove the seat. To remove the seat, lift the front of the seat and slide it forward. It is held in place with two rubber bumpers.
3. Remove the air filter cover. The air filter cover is located on the left side of the motorcycle, just behind the front wheel. It is held in place with two screws. Remove the screws and lift off the cover.
4. Remove the old air filter. The old air filter is located inside the air filter cover. Simply lift it out of the cover.
5. Inspect the air filter. Inspect the old air filter for dirt, dust, and other debris. If it is dirty, it is time to replace it.
6. Install the new air filter. Place the new air filter into the air filter cover. Make sure that it is seated properly.
7. Replace the air filter cover. Replace the air filter cover. Tighten the two screws that hold it in place.
8. Replace the seat. Slide the seat back into place and lower the front of it.
