Step 1 – Go to Dashboard > Plugins > Add New.
Step 2 – Typoe WordPress SEO by Yoast in the Search box.
Step 3 – Click the Install Now link.
Step 4 – A pop-up alert box will ask if you really want to install the plugin, click OK.
Step 5 – In a few seconds the plugin will be automatically downloaded and installed. All that is left is to click on Activate Plugin.