Use dpkg to view changelog

dpkg does not provide any facility to read the changelog of a package. you should extract the package and read the changelog

dpkg -X <package.deb> <folder>

then you can read the changelog using the dpkg-parsechangelog utility

dpkg-parsechangelog -l <folder>/usr/share/doc/<package>/changelog.Debian.gz

Since that's a real pain , if your distro is using apt-get you can use

apt-get changelog <packagename>

or

apt changelog <packagename>

If the package is installed, you just go to /usr/share/doc/<package_name>/ and there you will find the upstream ChangeLog and the Debian (package) changelog.

Possibly the files are gzipped, in such case, you can use zless to view them.