Searching for Stanley sliding door top glider 3750337

Thanks for writing in. Take a look at our 23-093. The part number you cite has been associated with this roller in the past, but keep in mind that this roller has a spring adjuster. A very similar roller, the 23-027, has a screw adjuster instead. If you have an undamaged version of this roller available, just confirm that it has a spring adjuster like our 23-093. 

As for removing it, there is no way to do so without taking the door off first. You will need to adjust your rollers enough to give your door clearance and then lift it out. They simply hook into the door. They can be set pretty firmly, so it might take some effort to get them out. We usually use needle nose pliers to sort of wiggle them out.