how do i change the check engine light

I have personally never experienced a check engine light needing changed, as it is usually a built in component of your dash. If it is stuck on and you have already fixed an issue, you can unplug the battery and turn your ignition to fully drain whatever charges are left in the vehicle. If it's just not turning on at any point and you need it to, chances are very high that it is not the actual check engine light that needs fixed but rather a short or fuse that is making the light not function correctly.

You can access the back of the dash and check if the bulb is burnt out but like I said earlier I have not experienced this issue and I have never heard of anyone that has without serious water/electrical damage I doubt it would be possible, especially on a car less than 20 years old.