Put on gloves to protect your hands.
When prying with a flat-tip screwdriver, wrap it with protective tape, and apply protective tape around the related parts, to prevent damage.
Take care not to scratch the body surface.
After loosening the mounting screw, then remove the A pillar garnish (A) by using a screw driver.
Relplace the A pillar garnish to a new one.
Install in the reverse order of removal.
Replace any damaged clips.