Josh- The answer depends on what spec crank you have. Are the rings held together by rivets that are made to look like screws (chainring bolts)? Or actual bolts? Some of the bolts use 5mm some use 6mm and some use a Torx fitting. Almost all the time you'll have to remove the crank arm from the BB axle to get the freed up granny ring off. This removing the arm makes getting at the bolts much easier. The removing of the arm usually does need a specific tool (a crank arm extractor and a retaining bolt wrench for the common tapered square designs). So the answers to both ring removing, tools needed and whether replacement arm is needed depends on what you really have. For some reason my X-Ray and telescopic vision is down tonight, or I'd have just looked at your crank and given you the short answer... Andy.