Since the PNG already has a transparent background, you would just need to make it show up in Illustrator. This means you would have to enable the transparent background of Illustrator.

Steps to maintain transparency when resizing PNG images. Let's get real. ... Check for any white boxes that shouldn't be there, fuzzy borders, or backgrounds that are still there.

The next screen snapshot shows the difference in appearance between an image with a white background on a non-white background and an image with a transparent background. Topics Spotlight: New ...