How does one install it? just dump everything into the maps folder? (as well as making a backup of course) In which case, are they supposed to replace the old files? because they have a different file extension then the ones in the zip.
Whilst you're at it use this
http://tgq.nl/kentie.net/?article=d3d10drvIt's the best renderer for DX that's out. It also replaces the EXE and makes it more configurable (i.e. scalable UI at hi screen res).
If you have any problems with your computer just slowing down and crashing or anything like that go into the task manager, find the DX process and set affinity to one core.
I have a suspiscion that this mod uses one core by default but normal Deus Ex caused me a lot of trouble in the past with it's pooping itself over my modern PC.