http://www.thenissanpath.com/viewtopic. ... &start=540
Just go through the photos, you will see a few members without them. I am still contemplating about taking them off. I like the look without them but I like the ability to get to the roof for gear, kayaks, lumber, etc. and that they kind of deflect rock and road debris a little since I have a LE and don't have the splash guards. I think they are standard on at least the US models but I can be wrong. They are really just cheap plastic with a then metal bar inside with 3 brackets holding them up.
If I remember correctly, there are 6 studs on each side. You remove the boards from the brackets first. Then remove the nuts on the 12 studs to remove the running board brackets (3 on each side I believe, 2 studs per bracket).