I just did this to my S-trim. The correct way to do it is with a drill, a 3 or 4" spiral buff, and tripoli. This is the rough cut, which can be fairly light cutting or can take out dings, depending on how long and hard you use it. Once you're done with this step, you move to a 3 or 4" loose buff and use white rouge. This takes any hazing out, and makes the aluminum clearer and shiny. If your blower is just barely dull, then maybe this alone would work ok.
You're not going to hurt it by starting with the other step either. Both are very easy to work with. You can get the buffs and the compounds at eastwood.com.
One thing I'm not real up on is protecting it. I figure it's too hot for a clear coat of any kind... although Eastwood has a clear for aluminum engine parts. And I tried wax, but the wax dulled out the shine. The only thing I've heard of is zoop seal, which is often used on motorcycle engines. But it's like a C-note to buy that stuff. I'll just repolish it once in a while I guess.
