Posted: 21/08/2015 at 19:53
I've downloaded and added the image for you mrsail:
I fully agree with pansyface - you could find yourself in legal trouble if you breach the DPC.
One safe way of doing it would be to build a small retaining wall so there is about a 15cm gap between it and your neighbours wall. Remove soil in the gap down about 15cm below where it is now and refill with gravel up to the present level to provide drainage. Quite a lot of work though.