If you have the tbh app, you can download their all-in-one to get to stock(rooted) gingerbread. From there, you can flash liberty. This will allow you to do everything without the need for your computer.searayman said:
Note: I've had no luck with the deodexed all-in-one, but I've heard the odexed all-in-one works.
If you'd rather sbf, you gotta sbf back to froyo, then root using z4root, install droid 2 bootstrapper, then run the rooted gb update zip from tbh available at mydroidworld.com
Instructions for sbf from linux http://www.droidxforums.com/forum/droid-x-sbf/12015-complete-droid-x-sbf-flashing-guide.html#post106312
Link to mydroidworld for sbf route. Use method 2 http://www.mydroidworld.com/forums/droid-x-discussion/7651-official-dx-gingerbread-2-3-3-4-5-596-release-thread-something-everyone.html
If the all-in-one doesn't work (if you have the tbh app), then you'll be forced to use the sbf method.
Hope that helps..