This is for the coupe... i'm not sure if the sedan is the same...
Since this part can be changed while still on the door i see no point in going through the steps of removing the mirror from the car... although that option is there...
it's rather simple to do it has no screws or anything like that... it's just sticky stuff... a little bit of prying and it comes off ready for the new one...
quick video of how this is done:
YouTube - Removal of new civic mirror
now keep in mind that i took the mirror off a few seconds beforehand and the sticky lost a bit of it stickiness
so a little bit more pressure is needed than shown in the video... that does not affect the stickiness after it's set tho... it does get harder to take off once it's set again...
quick pic removed:
