Door Strut Replacement
The doors of an Aston Martin stay open on their own thanks to gas struts that hold them in place. The gas struts wear out over time and need to be replaced. You'll know when it's time to replace them because the door won't stay propped open. This is more obvious during the winter due to the cold weather, and functionality may return during the warmer months. These gas struts are formally called "door check arms" by Aston Martin.
DISCLAIMER: As always, follow all safety protocols. Don't undertake this task if you aren't comfortable with it and fully understand it. You are ultimately responsible for anything you do. Neither Redpants, LLC or myself is responsible or liable for anything that may occur.
New door check arms (gas struts)
T27 Torx bit with ratchet or driver
Small flat-head screwdriver
Floor jack and jack stands (or a lift)
Socket and ratchet for lugnuts
About 45 minutes per side
Although this isn't a technically difficult job, it will require a second person. They'll be holding and moving the door for you while you remove the old struts and install the new ones.
Before you begin, check to make sure your flat-head screwdriver is small enough to pop the retaining clips on the new struts. Do not remove the clips. You only need to pop them enough so the ends of the clips don't block the opening for the ball joint.
Break loose the lugnuts on the front wheels but don't remove them. You just need to loosen them enough that the wheel doesn't spin once the front of the car is lifted. Next, put wheel chocks behind the rear tires and lift up the front end of the car with the jack, then put jack stands in place. Make sure the car is securely supported before continuing. Remove the wheels and set them aside.
Use the T27 torx bit and Philips screwdriver to remove the fasteners on the rear half of the wheel well liner (fender liner). You don't need to remove the whole liner if you don't want to. Pull the rear half of the liner down so you can access the area behind it inside the fender.
If you look inside, you'll see the gas strut ("door check arm") in the fender, just below the mesh cover of the fender vent.
Your assistant will need to open the door and hold it in a position that allows you to reach the rear end of the strut with the flat-head screwdriver. If you look in the picture above, you can see that the strut goes through an irregularly-shaped opening at the back side of the fender. I found it easiest to have the door opened slightly - while the strut is still in the narrower part of the opening, then use the bottom edge of the opening as a leverage point to pop the retaining clip with the flat-head screwdriver.
Once it's popped, open the door a little more so the strut is in the wider part of the opening. This will give you room to pull the rear end of the strut down off of the mounting point. Be careful when you do this, as the retaining clip might pop back into place!
Use the flat-head screwdriver to pop the retaining clip on the gas strut closest to the front wheel. Once popped, pull down on the strut to remove it from its forward mounting point. You can now pull the gas strut out of the car.
Get your new gas strut ready to install by popping the retaining clips on both ends of the strut.
Have your assistant open the door so the mounting point on the door is aligned with the wider section of the opening in the rear of the fender. Install the rear end of the strut first - put the socket onto the ball mount and use the flat-head screwdriver to pop the retaining clip in place.
Have your assistant slowly close the door until the front end of the strut is able to seat on the mounting point. Put the strut's socket on the mounting ball and pop the retaining clip in to place.
Test the door to make sure the strut is secure and functional. If so, reinstall the fender liner and then repeat Steps 2 through 6 for the other door.