Please, I need help, This is my first bike bought used,, I looked at my muffler were it hooks to the manafold or motor, the bolts are broke coming out of the motor going to the manafold for the mufflers,how do change these bolts

 

Not sure about the CBR's, have not had to do it on mine. Most of the exhaust studs (bolts) are screwed in leaving, the half of the shaft exposed so you can mount & bolt on the header pipes. These can be undone, unfortunately & depending on the age of you're bike, the bolts need heat & a bit of expertise to get out. Especially if the studs are sheared (broken off level with facing of the exhaust outlet). In which case you're going to need a good set of Ezy outs, heat & a bit of expertise.