Fetch the packages from the FTP site, CD-ROM whatever. The filenames have the form name-<version>-pkg.tar.gz and are gzipped tar files. For a fresh install it is sufficient to untar the file at the top of the package hierarchy.
Note: If you are upgrading packages already installed, it's best to remove the old package first Removing Packages.
For example if we are installing the xemacs-base package (version 1.48):
mkdir $prefix/share/sxemacs/xemacs-packages RET # if it does not exist yet
cd $prefix/share/sxemacs/xemacs-packages RET
gunzip -c /path/to/xemacs-base-1.48-pkg.tar.gz | tar xvf - RET
Or if you have GNU tar, the last step can be:
tar zxvf /path/to/xemacs-base-1.48-pkg.tar.gz RET
For MULE related packages, it is best to untar into the mule-packages hierarchy, i.e. for the mule-base package, version 1.37:
mkdir $prefix/share/sxemacs/mule-packages RET # if it does not exist yet
cd $prefix/share/sxemacs/mule-packages RET
gunzip -c /path/to/mule-base-1.37-pkg.tar.gz | tar xvf - RET
Or if you have GNU tar, the last step can be:
tar zxvf /path/to/mule-base-1.37-pkg.tar.gz RET