Most profiling software automatically installs freshly generated profiles, but you will have to install many downloaded profiles manually.
Mac OS X. Profiles have the file extension “icc”. Simply move or copy the profile to one (or all) of the following locations:
Mac OS X
[a] These profiles are accessible to all users, but you will need administrator privileges to add or delete them.
[b] These profiles are only accessible to the specific user and can be added or deleted by the user.
[c] These profiles are managed by the operating system and should be left alone.
Adobe applications use an additional location (Library/Application Support/Adobe/Color/Profiles/) for some general use profiles and new profiles for working spaces (for example, when adding eciRGB as a general work space).
To uninstall a profile, simply delete it or move it to another location.
Windows. Windows profiles use both “.icm” and “.icc” file extensions. Right-clicking on a profile name calls up a context menu in which you simply select Install Profile. Profiles are stored in the following locations:
(The “c:” drive is assumed to be the system drive.)
You can uninstall profiles by selecting Uninstall Profile in the same menu. Avoid installing too many profiles, but keep copies of profiles you are not currently using.
You can download the Microsoft Color Control Panel or WinColor utilities from  (for XP only). This can be used to install and uninstall ICC profiles, as well as display and compare the gamut color spaces and profiles.
 You can use Windows “.icm” profiles, too.