replacing front bumper 97 corolla

Hi! I'm going to be replacing the whole front bumer on my 97 corolla,in my hanes manual I cant find any airbag info,I'm going to disconnect the battery before is start the job. does anybody know where the airbag sensors are located? a friend of mine told me that air bag sensors have yellow wires connected to them, is this true. any and all info would be greatly appreciated! thank's very much Dave in ct.