First you need a Programm that can cut out brushes of an picture and save it to a ppm file.
PerfectPaint or PersonalPaint would be a good choise. (Perfectpaint only can save 24 bit brushes in ppm and
if you use Personal Paint you have to switch off the "automaticly" button in the ppm Prefs.)
Please notice that other Programms maybe save the wrong PPM format.
Ok cut out the zensored area exactly! Save the brush in ppm format
In our case brush.ppm, then run unzens like this:
"unzens pic brush.ppm"
Now unzens save the unzensored version as brush.ppm.out, load that in your paint programm as a brush and
place it over the censored area...thats all:)