I've done a matrix replacement solo, so if I can do it, anyone can do it. Granted I did have the dash out, but I did still spend a lot of time upside down in the passenger door well. Took many hours but got there in the end and the car has been roasting hot since! As mentioned, dump all the bypass pipework in the bin. Did you know, the bypass pipework was an official VW induced recall solution in the 90s for the exploding matrix issue! I did a bit of reading about it when I was researching the job a couple of years ago, and was delighted to find that they could be dumped now in lieu of better quality matrixeseseseses'. Come to think of it, I probably read it here!