Ok please forgive me on this one. I just bought a 400ex and want to strip the plastics and give it a good wash so I can tear it down this winter. I don't know how to get the 4 black rivits out that hold the gas tank piece to the fenders. I don't want to break them so I wasn't to rough with them. My old warrior had all screws so these are new to me. How do I go about getting these out?