You need the original ISO or DMG. This is a 1.2GB file. (Verify the SHA-1 checksum if possible to avoid malware).
For users still running Mac OS X Lion (10.7.5) , it’s important to know the update status of Microsoft Office. microsoft office for mac os x lion 1075 updated
Search Microsoft’s official support site for: (Be cautious of third-party download sites.) You need the original ISO or DMG
: To ensure the best stability on Lion, you should aim for the last released update, which is version 14.7.7 Prerequisites : Before jumping to the final version, you typically need Service Pack 1 (version 14.1.0) installed first. Key Features microsoft office for mac os x lion 1075 updated