How do I install fonts on Mac OSX?
How do I install fonts on Windows?
How do I install fonts on my phone?
Installing a new version of the same font?
In case you’ve got a previous, older version of the same font installed already, you have to do the following before installing this new, updated version:

• Quit all applications (InDesign/Illustrator/Photoshop/etc)
• Deactivate and delete the old fonts
• Search for any files on your computer containing "AdobeFnt"
• Then delete those files which end with ".lst"*
• Install the new font
• Start up your application

*This is an Adobe cache thingie, which can cause trouble for Adobe programs when you have several versions of a font with the same name flying around. Delete these files first, if they exist.