if you're done any wrench turning before, this one's a snap. Once you've got the calipers off, just pop off the old rotor and pop on the new.

 

Fairly easy. I've done the front ones and a week later I'm in the process of doing the back ones (which are being a little more difficult). See my thread.

Take your time and make sure you have a mate over to help you do the pumping of the brakes when you're bleeding the lines.

There are some useful links on the X-Type FAQs page on this site. Some of the pictures and descriptions were a bit of a challenge (for a novice like me).

Or else buy the parts (Try EBC) and get a mechanic to fit - that way you'll save a few $ , and may be a bit of pain.... Good luck.

 

A 'horrible knocking noise' is probably something you don't want in your brakes. but it's also not something i've ever experienced.
change those rotors and pads first, (and bleed the system, while you;re at it!) and then let's revisit the noise if it persists. chances are very good that if anything is wrong with the brakes, you will find it while you;re swapping these main components.

 

Simple job, can be done in an hour. Nothing special to know.

Since you just bought the car, this would be a good time to take a good look around now that you have a wheel off - look at brake lines, cv boots, suspension parts, look for rust, etc.

 

Fronts are simple rears I hear are a little bit harder...

Never heard of the sounds you are speaking of. Try taking it to a rip off place like belle tire or whatever you have up that way. Belle tire would inspect the problem for free (but they usually add other things in on the quote that aren't the problem and don't need fixing.)

 

Rears are slightly more difficult simply due to the fact that you have to rotate the caliper piston back in. With the right tool it's not that hard, although it can take an inordinate amount of time to screw em' back in. The parking brake spring can be difficult if you let it.