The 2009 Mercury Mariner is a relatively easy SUV to maintain. Accessing the headlight is easy, as you only have to reach behind the housing for access. The engine air filter is easy to change on this car. You only need to disengage a few fasteners for access to the filter. Checking the brake fluid level is easy, as the fluid reservoir.
Some things are difficult on the 2009 Mercury Mariner. In order to access the spare tire, you will have to lower it from beneath the vehicle. This can be tough, as the components can grow rusted to the vehicle over time. To replace the parking light, you will have to peel back the wheel well lining for access. This lining can grow rigid and tight to the vehicle over time. While not too difficult, you will have to make a tough reach, and remove a few covers, in order to access the interior fuses.
Hans Angermeier has produced over 100,000 videos showing drivers how to fix things on their cars. He has broad expertise on basic repair procedures covering the majority of cars on the road.