pdf2ps a.pdf vim a.ps # take a look at it, maybe you see how the font is called cat a.ps | sed 's/Comic Sans/Times/g' > b.ps # may be sligh

pdf2ps a.pdf vim a.ps # take a look at it, maybe you see how the font is called cat a.ps | sed 's/Comic Sans/Times/g' > b.ps # may be slightly more complex ps2pdf b.ps