You need to have no major creases on An edge line or in a place that you can not make tool to get to. The home made "tools" are usually small and made of wood. It is basically hammer and dolly on a small scale. Very small hammers can be purchase cheaply from harbor freight. You take out the small dents as best you can using you improvised tools. Small hammer light taps until you are satisfied that more work will be counter productive. Spry the piece with Easy-Off Heavy Duty oven cleaner (yellow can). Let sit 20 minutes, rinse and dry. You likely will need to do this twice, second time 15 minutes. If you forget and leave it on too long it will pit the aluminum severely. Pay attention and DO NOT inhale this stuff or get it in your eyes. This process removes the very hard anodizing from the aluminum. Start with 220 grit wet or dry sand paper with water. Sand along the long axis of the piece. Use the 220 until all the scratches are gone and any high spots are removed. What you don't fix at this step will likely be visible when you are done. From this point on you are just trading large scratches for progressively smaller ones. The more steps in progressive finer paper you use the better the finished product. I use 220, 400, 800, 1200, 1500, 2000. Next you need 2 cloth buffing wheels that can be mounted to your grinder. If you lack experience with a buffing practice on something to develop technique. Too much force or the really wrong angle will damage/ruin the piece and possibly injure you. I use the Sears white and polishing compound, in bar form. Apply some to the wheel, doesn't take a lot and buff the piece. Apply a little bit frequently rather than a lot at one time, more is not better. If possible the last buffing pass should be on the long axis. Put the second buffing wheel on and use the sears blue compound to final buff. I'm sure there are other compounds that work as well and possibly better than Sears but it is available almost everywhere. The cost of re-anodizing is prohibitively expensive and not accessible to many people. So, you have two choices. Clear coat or leave natural (just wax). I choose to leave natural. This way if I need to touch up some minor scratches I can. It is a lot of work and requires patience. The results are very good and the cost is a very small fraction of what you would pay to have them professionally reconditioned ( I was quoted $150-$200 for each piece). If you have questions e-mail or PM me. I'll give you my phone number and we can talk. My typing skills are limited and exhaust me when I use them.
Good Luck,
Chuck
