Deinstalling has two flaws :
1) Deinstalling a package requires to deinstall all packages which
depend on it.
Yes.
2) The dependencies may be used by other packages, so they may not be
orphaned. If you deinstall all the dependencies too, see 1). As many
packages depend on libc6, you'd end up deinstalling almost all the system.
This might be a problem, of course.
Instead I'd use this :
apt-get --reinstall install <package list>
Maybe if he can specify the package with the corrupt file, I would delete the
file, then download it and then manually install it with dpkg -i package --
overwrite.
Happy hacking
Hans