Step 1: Open a Google Sheet project
Step 2: In Google Sheets, click the Add-ons pull-down menu and select Get add-ons.
Step 3: Type "Yet Another Mail Merge" in the search bar
Step 4: Click on the button Install to install the add-on
Step 6: You have now successfully installed the mail merge add-on for Gmail, for instructions on how to use this add-on please see our Using Mail Merge in Gmail solution