In the example below it reinstalled and older version of a dependency (jQuery).
Id Version
-- -------
EntityFramework 4.1.10331.0
jQuery 1.5.1
jQuery.UI.Combined 1.8.11
jQuery.Validation 1.8.0
jQuery.vsdoc 1.5.1
Modernizr 1.7
PM> update-package jquery.Validation -reinstall
Successfully removed 'jQuery.Validation 1.8.0' from MvcApplication34.
Successfully removed 'jQuery 1.5.1' from MvcApplication34.
Successfully uninstalled 'jQuery.Validation 1.8.0'.
Successfully uninstalled 'jQuery 1.5.1'.
Attempting to resolve dependency 'jQuery (≥ 1.3.2 && ≤ 1.6)'.
Successfully installed 'jQuery 1.4.4'.
Successfully installed 'jQuery.Validation 1.8'.
Successfully added 'jQuery 1.4.4' to MvcApplication34.
Successfully added 'jQuery.Validation 1.8' to MvcApplication34.
PM> get-package
Id Version
-- -------
EntityFramework 4.1.10331.0
jQuery 1.4.4
jQuery.UI.Combined 1.8.11
jQuery.Validation 1.8
jQuery.vsdoc 1.5.1
Modernizr 1.7
Id Version
-- -------
EntityFramework 4.1.10331.0
jQuery 1.5.1
jQuery.UI.Combined 1.8.11
jQuery.Validation 1.8.0
jQuery.vsdoc 1.5.1
Modernizr 1.7
PM> update-package jquery.Validation -reinstall
Successfully removed 'jQuery.Validation 1.8.0' from MvcApplication34.
Successfully removed 'jQuery 1.5.1' from MvcApplication34.
Successfully uninstalled 'jQuery.Validation 1.8.0'.
Successfully uninstalled 'jQuery 1.5.1'.
Attempting to resolve dependency 'jQuery (≥ 1.3.2 && ≤ 1.6)'.
Successfully installed 'jQuery 1.4.4'.
Successfully installed 'jQuery.Validation 1.8'.
Successfully added 'jQuery 1.4.4' to MvcApplication34.
Successfully added 'jQuery.Validation 1.8' to MvcApplication34.
PM> get-package
Id Version
-- -------
EntityFramework 4.1.10331.0
jQuery 1.4.4
jQuery.UI.Combined 1.8.11
jQuery.Validation 1.8
jQuery.vsdoc 1.5.1
Modernizr 1.7