Now is the cabin air filter.
Tools needed....really sharp knife or dremel, gloves (show you why), flat head screwdriver.
The filter. It's a carbon filter so it gets that little extra out of the air. When I turn the ac on the air immediately takes that musty dirt smell where I work at away.
This cover will take a little figuring out on you own to get it to snap in. There will be times that it will trick you to think you got it but just do one side at a time if it gives you problems.
First off remove your glove box. It's simple. Just open it then on the top sides push it in and pull down. Viola gone.
Right when you get it open and look in you will see this. This will be where you cut and install the filter and clamp in the cover.
Before you cut take out your fan. There is three screws. This is where you will need your flat head. If your cutting and debris falls in and you don't know kiss yor fan goodbye.
This is how I cut it. No need to cut the small lower part. Also this might be why gloves is important maybe. There is a lot of sharp things under there.
You got to bleed for your truck.