So this was an interesting project.
Removing the Main Sliding Glass Door:
To remove the slider, you had to remove the black plastic track screwed into the top of the frame. You can remove two of the screws with slider completely closed, and the other two screws with the slider completely open. You can then slide the track our from above the door.
With the track out, you can lift the door off of the bottom rail, then tip the bottom out, now you can lower the door from the upper track.
Removing the rollers (trucks seems like a more appropriate word here).
1) Lay the door down on a flat surface.
2) Remove the machine screws at the bottom of the door frame. (not the roller adjustment screws)
3) Remove the bottom frame of the sliding glass door (It slides DOWN)
4) Inside of the bottom rail, will be phillips head machine screws. Remove these screws to remove the rollers.
5) Slide the rollers out the ends.
I took mine to a few hardware stores. I found exact replacements at Lowes. Take the measurements and there are a few online as well. I'll see if I can post a link to the model online.
NOTE: During remounting, you're going to want to have some heavy bedding compound. The gasket that mounts the glass is cut and exposes the corners of the glass. I had to remove the old bedding compound to expose the screws to the rollers which were underneath it. This required me to re-bed the corners again during installation.