I found this thread helpful with my install last weekend and thought I would contribute a few things I learned that were not mentioned. I installed the Eibach Pro-Kit on my 12 Civic Si Sedan.
I followed the jdmcity link as it seemed the most thorough and had pictures.
I started with the rear, just as the tutorial did. I'm not sure about the ex/lx, but the picture on the tutorial showed easy access to the bolt holding the lower control arm to the subframe. On my Si, there was a huge, plastic skid plate that had to be removed to access that bolt. Between the clips and bolts to remove the skid plate, it added an additional 20 minutes to my install time.
Second thing I ran into on the rear was reinstalling the spring. The tutorial makes it sound pretty easy, but it is not. This is defiantly a two-man job. I had to get my buddy to stand on the rotor to bring the control arm low enough to get the new spring in place. I also added lithium grease to the rubber mounts that hold the spring in place so it would slide in easier and to prevent any squeaking.
The last big problem I had was reinserting the bolt that holds the shock to the control arm. The bolt has to go through the mount and the shock perfectly to screw back in. It took nearly an hour to figure out what was going on here. I finally took a pneumatic wrench to it to keep the bolt spinning while I wiggled the shock in hopes of it eventually aligning correctly. This was the only solution that worked and I used it seamlessly on the second side. It took about 2 hours to do the first side and only 30 minutes to do the second. The joys of learning!
The install on the front was much easier. The first worry I had was accessing the top 3 nuts holding the strut to the frame. I was easily able to remove the access ports from both sides to gain access to the nuts without removing the entire windshield wiper housing. The access points just pop right off. There is one facing the front bumper and another on the side facing the fender. You can then see the 3 14mm nuts that need to be removed. I was able to access them all with a small socket/ratchet and just a 14mm wrench.
The last thing I learned that wasn't mentioned in the above tutorial was to jack up the control arm to release the pressure from the sway bar to remove the 12mm nut holding the strut to the sway bar. With the wheel removed and the control arm hanging freely, there is too much torsion on the sway bar and it doesn't allow for the easy removal of the bolt from the strut. Simply jack up the control arm to straighten the sway bar bolt to the strut and remove it without and torsion applied. Then, let the control arm back dow to remove the large bolts holding the strut to the control arm. This step would've saved me some time and frustration on the first side.
Other than those tips, the jdmcity tutorial was great and very helpful. I just feel these little things would've made my install much easier and smoother. BTW, I took my front struts to a shop and had them swap the springs out for me. I attempted to use the spring compressor bars and they just didn't feel safe. I decided to err on the side of caution with this one! I suggest anybody with some basic mechanical knowledge to do the spring install for themselves. Be sure you don't need your car for at least 2 days though, just in case you run into problems. It is very satisfying and I'm glad I know how all of my suspension works and that it was installed properly.