While it should be a relatively easy DIY repair, the vehicle needs to be on a lift, jack stands or blocks to do it safely. A 6-year-old vehicle will likely have the two bolts badly corroded, plan on using socket or box wrenches, not open ended ones, and some penetrating oil. Also plan on replacing the bolts. Be certain to remove all the old gasket material, and sand the mating surfaces smooth before installing the gasket.
The guy at the Mazda parts counter will be able to get you the right parts.