Open Propellerhead Reason. Depending upon your program settings, you will either see a pre-created sample song or an empty document. If you see the sample song, click on "File" in the program's main menu bar and select "New" from the drop-down menu provided. This will create an empty song file to work with that contains the Reason Hardware Device, an M-Class Mastering Suite and a 14:2 Mixing Board to plug your NN-XT into.
Right-click in the rack window, the upper portion of Reason that displays your digital audio devices, and drag your mouse over the "Create" selection in the menu that appears. A list of all the devices you may use in your project will be presented. Select the NN-XT Advanced Sampler from the list. The device will appear in your rack window and will auto-connect either directly to the Reason Hardware Device or to the 14:2 Mixing Board if you have one hooked up.
Click on the hide/expand arrow in the lower-left corner of the NN-XT. This will cause the device's Remote Editor to drop down.
Click on the envelope button that says "Load Sample" next to it in the Remote Editor. This will cause a window to pop up in which you may search your computer for audio samples to add to the Editor. Any WAV files will do; you may record your own samples in programs such as GarageBand and ProTools, but if you are not experienced in doing so, websites such as sampleswap.org and freesound.org provide an abundance of free samples that you may download and use. (See Resources) Click on any samples you wish to add to your patch while holding the "Shift" key on your keyboard and then click on the "OK" button.
Select "Automap Zones Chromatically" under the "Edit" tab in Reason's main menu bar, which will assign every sample you added to a key position in the NN-XT. Make sure you have the NN-XT selected when you do this or the "Automap Zones Chromatically" option will not appear in the menu. If you have a MIDI keyboard plugged into your computer, playing the keys on it will trigger the samples assigned to the corresponding keys in the NN-XT's blue display window. If not, hold down the "Alt" key on your computer's keyboard and click on the keys in the display window.
Save your patch by clicking on the "Save Patch" button in the NN-XT's global settings, which is indicated by a picture of a floppy disc. Choose a location for your patch, name it and press "Enter" on your computer's keyboard.