You will have to determine the current speaker configuration in your Civic. If you have 6-6.5 inch round speakers in the car, these will work for you. You will have to unplug your current speakers, remove the nuts that attach the speaker assembly to the rear deck of your car and then remove the whole assembly. Once out, you can detach the speakers and check the hole alignment. If the speaker size fits, but the holes do not align, you can carefully drill holes in the outer flange using the old speaker as a template. Then simply install in the reverse order of disassembly. Hope that helps.
I believe they only fit in your doors ,so you must remove the door panels remove the old speaker and install the new speaker and replace door panel it's some what difficult you may want to watch on YouTube first