On your car, I think the fuel filter is located on the firewall and looks like a little can-looking thingy. It's about 3 inches in legth and is usually black.(This is if you don;t know where it is). First I would take your gas cap off to relieve some pressure so it doesn't squirt everywhere. Then just crack the bolt on the top of the filter and then take the bolt out along with the fuel line. Next is to dismount it from the fire wall. Make sure you put a rag over the wrench and bolt because fuel could squirt from there. Also, if the new filter doesn't come with washers for the bolt and line, I would be careful to not lose the existing washers.
For your next question, your Civic can't go faster than about 120. People say they've gotten past that, but who knows. Only way to get it past that mark is to start making more power.