If possible, try to work in an environment with minimal dust. The goal is to try to avoid dust from getting inside of the lens as much as possible.

Remove the two 3mm JIS #000 screws on the side of the lens mount.

Remove the four 8mm JIS #000 screws holding in the metal lens mount.

Do not pull up on the lens mount assembly. The contact assembly is still attached and you'd risk damaging the ribbon cable.