E: Valve Stem Seal Removal
WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.
Use special tool MB992085 to grip the base of the stem seal (where the outside diameter is larger) securely, and remove it by twisting it to the left and right.
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.