Walk through the installation wizard, accept the licensing terms, and select your installation destination.
If you are on a newer Mac (macOS Catalina to Sequoia), consider these options: Moving MS Office 2008 from 12-yr old iMac… download microsoft office 2008 dmg for mac os link
Product keys are usually on a yellow or orange sticker on the CD sleeve or documentation. Different editions allow installations on different numbers of Macs: Walk through the installation wizard, accept the licensing
: It requires Mac OS X version 10.4.9 (Tiger) through 10.14.6 (Mojave). Walk through the installation wizard