I would like to modify a raster (pixel values) in QGIS.

The plugins "value tools" can easily provide me with the value of the pixel of my raster. However I don't know how to modify it.

I have found this tread saying it is possible to do it in Grass (thread). I'v spent several hours on trying to understand how grass works without success.

I can't find the d.rast.edit tool in the sextante plugin. Is there another way to acess it?