First off welcome "wadd55".

Second thing is buy some books on the subject and when you feel confident, always measure TWICE and cut ONCE. You can read about this stuff on the internet as well. The eastwood co. offers supplies as well as books and video's on the patch panel replacement although they will not tell you what to do first on your particular application.

Take careful measurments and make a sketch with those measurements. Remove the door if you havent already and go slow...don't rush. Post some pix showing the areas to give us a better idea of what needs to be done and how bad it is. You can refer back to the photos later as a visual reference. I am willing to bet someone on here already did that and can give you more precise advise.

Dave