Only works if you're rooted. If you don't have Root Explorer, download Root Browser Lite from the market, it's free and works fine for this.
Open the root file manager you have (Root Browser, Root Explorer, etc) and navigate to /system/. If using Root Explorer, mount that directory r/w. Long press on the build.prop file and open with a text editor (root browser has one built in, not sure about Root Explorer). Edit the line in the rootzwiki link I posted. Just change EP4 to FP1. Save the file and reboot your phone. If you don't have data when it boots, reboot again. I only had to reboot once.
That's it.