trouble: plotting without stamp

when i open dwg file the window appears noting that the drawing will plotted with stamp (see attachment)

how to remove that stamp text?

printscreen.pdf

That stamp can't be removed, it's Autodesks way of letting people who don't know that the drawing was done at an educational level and as such for work outside (I.E. for profit) is not allowed.

Correct. Don't use content created in an EDU version of AutoCAD for commercial purposes.

See also: http://usa.autodesk.com/getdoc/id=TS63668