The following steps describe how to download and install or reinstall Office 365, Office 2016, or Office 2013.

Install or reinstall Office from My Office Account

If this is a new copy of Office and you have to redeem it online using the office setup page as linked here.

The office setup asks you to enter the 25 character product key. Note that Office 365 once redeemed on a Microsoft Account cannot be used on the other account for a new setup.

Office 365 Home Premium allows you add additional family members with their to your program. Henceforth,they could be able to access the shared program from your account.

Refer the steps here