Need help with oxygen sensor

My car has been showing the check engine light for quite sometime now! I went to Autozone and they did the free check up thing and they found out that bout the oxygen sensors are messed up! now what can i do? i would like to exchange them but is there any way to make sure that the check up is correct! and at the autozone the front one is 81.99 and the rear one is 69.99 is that a correct price?

can anyone provide me with a how to video or something on how to replace these?

thank you ahead of time!

First just replacing the O2 sensors may not fix the problem. If you have over 100,000 then it is time anyway. Call around for prices. They can very. You will need an O2 socket to get them in and out.

Those prices sound about right. Autozone has a loaner tool set that has an O2 sensor socket in it, they'll let you borrow it free. Just unplug, unscrew, screw in the new one, plug it in, and you're done. Do it with the exhaust cold. It may take a few drive cycles for the light to go out. It took mine about 3 trips, then it went out.