It depends on what kind of fret wire you have. Here is a pic so you can understand me::http://liutaiomottola.com/construction/FretInstall_files/fret.GIF
Most kinds have either a barb or a flanged tang so that they don't slip out. The result is fret wire that can be difficult to remove.
To remove it (carefully) requires a special set of pliers - http://www.guitarsetup.co.uk/img/refret/large/fret+removal.jpg
- that are tailored for this purpose. You can find them online and at some local guitar repair shops. You could use wire cutters and get the same effect I suppose, but keep in mind that you should always use the right tool for the job.
Start at one end of the wire, and slowly pull it up at small intervals. Move along the length of the fret, pulling it up little by little. If you try to rush it, you can end up damaging your fretboard as the barbs come up, especially if you have hardwood fingerboard (it splinters).
Start with the highest fret - if you mess up, it isn't as big of a deal because the higher frets on a bass aren't used much (it kinda defeats the purpose, lol).
If you find that you cannot get the frets out, and still don't want to go to a professional, you can a grinder (note - this is NOT a sander) or dremel drill very tenderly to the frets. You will mar your fretboard - be warned. AND this method IS permanent. You cannot go back.
One HUGE note. Because you aren't a trained luthier, it is likely that you might damage your bass. If you truly feel like you will never want frets back on your bass, it isn't a big deal - just fill your mistakes with wood putty. But keep in mind that you might decide in the future to refret your bass, you might have done too much damage to it to fix.
It would be better for you to find a bass neck that hasn't been fretted yet and swap it out for your current one. As long as you have the same scale neck and you install it right, it will be much less work. Then, if you decide that your bass sounds better with frets, you can always swap it out in 10 minutes. They start at $135 at allparts.com