Site Owners Forums - Webmaster Forums - How to use of Disavow tool?

Google’s Disavow Links Tool is one of the best SEO Tool utilizes to save your website from harmful link By removing it from your website.

Disavow backlinks
This is a two-step process. First, you’ll need to download a list of links to your site. Next, you’ll create a file containing only the links you want to disavow and upload this to Google.

Download links to your site
* On the Webmaster Tools homepage, click the site you want.
* On the Dashboard, click Search Traffic, and then click Links to Your Site.
* Under Who links the most, click More.
* Click Download more sample links. If you click Download latest links, you'll see dates as well.

Note: When looking at the links to your site in Search Console, you may want to verify both the www and the non-www version of your domain in your Search Console account. To Google, these are entirely different sites. Take a look at the data for both sites. More information
You’ll download a file containing all the pages linking to your site. Use this to create a text file (the file type must be .txt and it must be encoded in UTF-8 or 7-bit ASCII) containing only the links you want to disavow—one link per line. If you want Google to ignore all links from an entire domain (like example.com), add the line "domain:example.com". Your text file can include additional information about excluded links, as long as each line of description begins with the "#" character (all lines beginning with # will be ignored). Don't upload the entire list of links to your site: the text file that you upload is the list of links you want Google to ignore.

Example
Here's a sample of a valid file:

# example.com removed most links but missed these
http://spam.example.com/stuff/comments.html
http://spam.example.com/stuff/paid-links.html
# Contacted owner of shadyseo.com on 7/1/2012 to
# ask for link removal but got no response
domain:shadyseo.com
If you want Google to ignore all links from an entire domain (like example.com), add the line domain:example.com.

Upload a list of links to disavow
Go to the disavow links tool page (https://www.google.com/webmasters/to...vow-links-main).
Select your website.
Click Disavow links.
Click Choose file.
Note: Uploading a new file will replace all previously uploaded ones.

It may take some time for Google to process the information you’ve uploaded. In particular, this information will be incorporated into our index as we recrawl the web and reprocess the pages that we see, which can take a number of weeks. These links will continue to be shown in the Search Console inbound links section.