Most of the freeze plugs are located in the engine block on both sides of the block. They may be of different sizes (diameters), there are usually a few smaller plugs in the cylinder head and or intake manifold. They are used to facilitate the casting process of the engine. They may rust out and leak if the cooling system is acidic or coolant becomes rusty. You may be able to get a number count on www.rockauto.com and can find the repair/replacement procedures in any of the below sources. Autozone have some popular workshop manuals for free on line once you register (for free) on their website http://bit.ly/autozone_repair_infoThere is a company that independent auto repair shops "buy" their information from that offer a very reasonable service to do it yourselvers. You get a one year subscription to year make and model specific repair procedures, service bulletins, component locations, wiring diagrams ect.... great quality information same as the professionals have ,much better than generic workshop manuals from parts stores, much cheaper than the factory manual. http://bit.ly/alldata_repair_manuals or try http://bit.ly/mitchell_repair_manuals_online and get an online repair manual subscription.