removing decals and stripping paint

Can anyone advise on how to remove the decals and strip the paint off of an aluminum frame bike? I've only seen this done on some bikes but not sure how the owners performed it. Thanks in advance,

JS

It's done with a big pile of sand paper and a lot of free time. You can probably find an auto body shop that can bead blast it for you. That won't erode the metal like sanding will, and they'll have it done in less time than it would take you to do the head tube.