How do I remove unnatural links from my blog?
 

I worked too much to gather do-follow links for my blog, after some time I found my site's ranking is being dropped and I used the disavow tool to remove these links but I think to disavow tool does not work or I can't use this properly.

Suggest another way to do this effectively that works but except contact with website owner or webmaster?

Identify your bad links (you'll find how exactly from this article)
Search for the contact information of the website you have the link on
Contact the webmaster asking him to remove the link
Disavow the links and upload the file to Google

by using Disavow tool

Identify your bad links (you'll find how exactly from this article).
Search for the contact information of the website you have the link on.
Contact the webmaster asking him to remove the link.
Disavow the links and upload the file to Google.