Don't use steel wool!
The dust will just end up stuck all over your pickups because of the magnets in them.
Go to Lowes and get some of these: http://www.lowes.com/pd_335873-98-10...pad&facetInfo=
That is the Grey, but you probably also want Green and White.
Green is the most coarse, Grey is in between, and White is the least coarse.
Hit your rough spot with the green until it feels smooth. Then you could probably just do the whole neck with the grey, and then the white. That will ensure the whole neck feels consistent.