I noticed in your "Introduction" thread that you are looking for a setup file for the X5. Unfortunately, I'm not sure that's going to be possible unless someone here has an X5 that they have already setup.
However, don't fret...there is still hope. We just need to start from the beginning.
Is this the X5 that you have?
Skywalker X-5 FPV / UAV Flying Wing 1180mm
You'll need to setup the wing type. Press and hold the scroll wheel on the DX8, then turn it on. This will take you to "System Setup". Select the Model Type: Airplane. Enter your Model Name. Then let's go to Wing Type...scroll over to Elevon. There probably isn't much to be done in the Switch Select unless you have some other special features. You should go to the Warnings menu and set a warning of some type for the Throttle....just as a safety feature. Go to your Frame Rate and select 22ms if you have analog servos on your X5. You can select 11ms if you are using digital servos. After all this is done, you can click "BACK" and go to the Main Menu.
In the Main Menu, you can go to the Servo Setup and D/R and Expo menus. The menus are pretty much going to be up to you and your preferences.
Don't forget to scroll down to the Timer menu and set a timer. I prefer a countdown type.
I hope this helps get you started. If you need further help, post your questions. We'll be around!