If you wish to reach to the A/C blend doors or maybe just looking for something behind the glove box of the 99-04 Jeep Grand Cherokee WJ, you will have to “drop” the glove box.
If order to do so, you do not need any special tools (or any tools at all).
All you have to do is reach your hands up when the gloves box is open and pull 2 rubber parts which hold it from dropping.
As you can see in the pictures below:
(The rubber parts in the pictures had been pulled out most of their way in order to be visible in the pictures, you do not see them in normal state)
That is the rubber part you should look for:
Here are the locations, one of the right of the gloves box (the first picture), notice the slot under it), the second one is on the left.
Installing it back in place is simple, while it is down’ insert the rubber parts to their location and push the gloves box to its place. It will push the rubber and be in place.