From the looks of it, the bottom of your faucet has a screw-in aerator. Faucets typically use standard inside thread dimensions, so you should be able to use any screw-in aerator that suits your taste.
To remove the existing aerator, try applying masking tape to both jaws of your pliers to prevent damage to the aerator in case you need to use it again. Then grasp the aerator and unscrew, turning counter-clockwise. This should allow you to remove the old aerator and see the inside threads of the faucet. Simply screw in you new aerator and you're set. You might need to apply some Teflon tape on the threads of the new aerator if you see any leaks, but it's generally a good idea to use it for male-female threaded plumbing components.