Chain rings
Chain rings are either held together by rivets or bolts. Avoid owning a bike with chain ring rivets if possible, as you will have to destroy your chain rings and your right crank arm if you need to take apart/ repair the chain rings for any reason.
Taking apart bolted chain rings requires one special tool. It's a screw driver with a notched head design to fit a chain ring nut. Any bike shop should have them.[1]