I assume you are working in a web application as you are asking for a link...
Place your excel manual file in your website project (let's say in a folder called 'Manuals'), on your solution explorer click on 'show all files', then navigate to your file, then right click on it and select 'Include in Project', right click again and click on properties. In the Properties dialog box you click 'Copy if newer' instead of 'Do not copy'.
At that point your manual will be copied with your deployment files.
Now on your webpage you can put a link like
<a href="/Manuals/filename">Download excel </a>
Should be all good...