The gas cap release for a Mitsubishi Diamante is located in the trunk, on the left side. There is a cable with a handle on it running down from the top left of the trunk, and you'll need to pull it to manually release the gas cap.
On the driver side door just above the little storage spot there are two buttons one is for gas cap, and the other is the trunk....
Simple... You remove the wheel from the car and punch out the center cap from the backside of the wheel.
Remove the center console/cupholder. Remove the interior doghouse. Remove distributor cap.
There is an oil cap on the top of the valve cover. Remove the cap, add some oil.
Screwdriver
The only way to remove it without damaging it is to remove the wheel and tap cap off from the inside.
Remove the center cap, washers and C-clip and the wheel should slide off.
If it is like the Deville models, you should have a special tool that will remove the center bolt. The owners manual will have a picture of this tool. Use the flat edge of the tool to remove the center decoration, and then use the rounded end to remove the center bolt. The hub cap will then basically fall off.
on the 420a its located right in front of the radiator cap. remove the 2 bolts(10mm) and there it is
you just take it to the car shop and let them do it
To access the rotor, remove the tire and brake caliper. There will be a cap protecting the bolt that holds the rotor onto the spindle. Removing the cap, located in the center of the rotor (on the spindle, not the rotor itself) will allow you to get access to the bolt. Removing that bolt frees the rotor from the spindle.