1. it will take you a good 5 hours with both of you. he knows the fundimental basics but i doubt he'll know the civic well. he will have to find routes and such to wire it.
you'll need to take out door panels, rear panels, run speaker wire, take the head unit apart, wire and run the power wires through....etc.
2. you might need 1" spacers in the front depending on how deep your front speakers are. your sedan uses 6.5" speakers all around. so you will have to modify your rear to fit them with proper spacers and such.
3. if you are running a double wire (has both + and -), you will need at least around 50ft of speaker wire. you will need about 10ft of power wire (no less than an 8 awg). 4awg is a good compromise between cost and power...
4. post picts. go look at the DIY for the headunit removal. keep us updated.
post questions on here. you can email me if you want a faster response (or just email to notify you need a response on the forum. firstname.lastname@example.org