How to Replace Performance Air Intake Kits for a 1993 BMW 525I

1. Turn off the BMW 525i engine and open the hood.
2. Remove the hose clamp around the air intake tube that is already installed using a flat screwdriver. Remove the two nuts holding the mass air flow sensor onto the intake tube.
3. Pull off the plastic alternator cooling pipe and release the clips on the other side of the mass air flow sensor and remove the four bolts holding the air box to the fender wall using the ratchet. Pull the entire air intake system out of the BMW's engine compartment, including the air box.
4. Remove the two bolts holding the mass air flow sensor onto the old air intake system and remove the sensor from the air intake.
5. Use the ratchet to attach the shorter of the two mounting brackets to the two rear holes that the air box previously was bolted to. Bolt the other mounting bracket to the two remaining air box bolt holes.
6. Place the cone filter onto the open side of the mass air flow sensor with the mass air flow sensor's 'O' ring between the two. Tighten the filter's hose clamp to secure it.
7. Place the performance intake system back into the vehicle, reconnecting the nuts removed in Step 2. Place the alternator cooling pipe back into place and close the BMW's hood.