It's not too difficult, jack the car up as high as you can and support it with an axle stand at the rear of each sill and you should have enough access. I did mine ok like that and my coilovers are as low as they can go.
Use a small grinder to cut to old system close to the back box, remove the backbox first. Then you'll be able to remove the rest of the system from the cat without any issues.
Set aside a couple of hours start to finish
