If it matters that much, I'd look into just contacting the manufacturer and replacing the driver. If you have nothing to lose anyway, a dab of hot melt glue (the kind they use for paint-less dent removal on automobiles) and then attach something to it while still molten like say, a wooden chopstick and then let it set. It may take some strategy in where to attack it first, in the event it takes several attempts from different locations/angles. If it's deeply dented/creased, all bets are off.
I've removed the felt caps from paper woofers without destroying the cones. Perhaps the aluminum dome can be heated with a soldering iron, just until it solves the adhesive they are adhered with (if the speakers are constructed that way) gives up enough for them to be removed and body worked from the reverse side and glued back. I have reformed thin aluminum (paper thin fuel injector stack) with a small wood dolly shaped to fit the part and then formed on a canvas pouch filled with beach sand.
ETA: They sell aluminum speaker dust caps of all different sizes online. Perhaps you can find one that fits or can be resized to fit if you can get yours off.
