Got to change my brake lines, have a MOT coming up in October and on my last MOT the front brake pipes were borderline rusty.

Have a few questions if anyone can answer them...

Is it a easy job to change them?
Do I have to physically go under the car? (hopefully not as I have no extra supports for jacking the car up, only the standard BMW jack)
What material is best to use for the pipes? (I see copper pipes is cheapest)
Do I need any other tools except for spanners and sockets?