I need help with my Dorwal door

First, as you said, you will have to remove the stationary door. There should be jamb clips holding it in the track near the head and sill. I also recommend that you remove the doors from the outside. Check out the guide below for more information.

You should have two clips similar to our 80-003. They will be located inside on the jamb-side of the stationary door. One will be near the top and one near the bottom. You might also just have one in the center. Remove them, pull the stationary door over, and lift it out. If it still wont come out look for any other type clips on the other side of stationary door near the top that could be preventing you from lifting the door off the track.