Do yourself a favor and go buy some Anti-Seize.
Anything screwed into the aluminum frame needs this stuff.
Here is the result of the factory not using anti-seize on a steel screw in an aluminum chassis.
I started with a #3 phillips and the first one came out with a "pop". The second started to strip the head so I stopped. I then used a pair of vice grips on the screwdriver while I put all my weight on it. I thought the bike would lift the front tire, pivoting on the center stand, but no luck. I then used #3 bit in a 1/4# drive ratchet with a board on top to put my weight on, no luck. I popped it with a brass hammer. I cut a slot in the top with a dremmel to us a big honkin flat blade and some vice grips, no luck. I soaked it in liquid wrench, but ho help. As a last resort, I cut out the grommet, ground the washer down and took it out by the head using a pair of vice grips grabbing at a right angle.