I think the guide below is correct. Someone will be sure to point out anything that's changed since I last posted this
First off, your profile must be a profile with Administrator rights. If not, switch to one that is.
Download and install the Obsidian Launcher.
You must have it set to run as Administrator (right-click the icon, go to Properties, click on the Compatibility tab, then 'Run this program as an administrator'). This is in addition to running on a profile with Administrator rights.Download some fonts (various options at
http://www.saberforum.com/index.php?board=36.0, or at
http://www.ultrasabers.com/Sound-Font-p/soundfont-manual.htm) and extract them to a folder
Make sure your 'sabre is fully charged before plugging in. If your batteries die mid-transfer, you can mess it up.
Switch on your lightsabre and plug it into a USB port. Wait for it to install on your computer
Load up the Obsidian Launcher program. Your lightsabre should power down, and in the top right of the Launcher screen you should see the serial number of your 'sabre
Clear the right pane of the Launcher window of any fonts that may be there.
Navigate in the left pane of the Launcher window to where you have your fonts installed
Drag the .lsu files over to the right pane. So, for example, the Yoda font I downloaded has poweron.lsu, poweron2.lsu, poweron3.lsu, poweron4.lsu, poweronf.lsu. You'd put one those into the Power On section. The Motion, Lockup and Impact sections can have more than one option loaded.
Continue until you're happy with the selection of fonts on the right side of the window.
(Optional) Save the configuration file - I have all mine in the Ultrasabers folder (that the Launcher installs to by default) for convenience, along with all the font folders
Click on the round button with the down arrow in it. You'll start to download the fonts onto the 'sabre.
There's a check box on the progress window. It says something like 'verify integrity' or something. Best to check it.
Once it's complete, close the Launcher, unplug your 'sabre, and enjoy the new sounds.
Also, you can mix and match sounds - Starkiller power up, Sith swings, Yoda clashes and so on.
Hope that helps!