What I'm going to say will probably sound like heresy, but if you aren't comfortable with soldering copper pipe, your best bet will be to open up the access panel, clear the area around it and call in a plumber to make the connections for you. It is real easy if you don't have much experience sweating copper joints together to end up with pinhole leaks which will turn this little job into a bigger one and you'll end up wasting a whole day on a simple faucet replacement.