This is the upgrade procedure for tetex. There is a serious problem/bug in dpkg that prevents the correct removal of the old tex packages and then the installation of tetex.
dpkg can't handle multiple packages which are to be replaced. So, do the following: - Purge all the old tex packages which are replaced by tetex. (E.g. go into dselect, select the tetex-packages, look which old tex packages are marked to be removed, purge the packages.) tetex replaces: amslatex, amstex, babel, bibtex, dvipsk, kpathsea, kpathsea-dev, latex, latex2e-doc, ltxmisc, ltxtool, makeindex, mfbasfnt, mfdcfnt, mflib, mfnfss, ps2pk, psnfss, texbin, texi2html, texinfo, texlib, texpsfnt, textmf, xdvik - Purge latex before you purge mflib, because the postrm script of latex depends on install-fmt-base, which is in mflib, but latex does not depend on mflib. This is a bug in the old latex package. - Watch out that all config-files in /etc/texmf/ are removed, at least texmf.cnf is incompatible. (dpkg --purge should do this for you.) - Install the tetex packages. Don't install tetex over the old packages with --force**. You will get an inconsistent system.