Is there any way to remove bad links from the links built already?

add your site link in to the htaccess or robot.txt with block tag.

Depends. If it is just a handful you can try contacting the webmaster to physically remove them and that may work. If it is many "bad" links then you may be out of luck. The thing to remember is to NOT try to manipulate your backlinking strategy by artificially building links. Let backlinks generate themselves naturally, or not generate themselves altogether. I honestly don't think it matters much either way if your web site has already established trust with the search engine because of its history of offering evolving and valuable, uniquely important content.

Well said seoaceindia. By adding the bad link in robots.txt alone is enough to remove the links.

You can delete those links or you can create a text file and upload it with Google's disavow link tool.

Disallowing the link in a robot file doesn't remove it from the face of the Internet nor does it stop the search engine from continually acknowledging it's existence.

It's all such a waste of time in 2015. Because of excessive manipulation over the years, the vast majority of links haven't much good or bad influence to begin with, if any. It surprises me to observe web developers still trying to link juice-up their web pages rather than building better, evolving content for their web pages. Deploying any artificial link building strategy is a worse thing to do today than ever before because it can only be done poorly, all the clever ways to manipulate links have already been exhausted.

Try to utilize Google Disavow tools to remove bad/spam backlinks from your website. However, you should definitely need Google Webmaster access to remove (disavow) unwanted or bad backlinks.

you must use google disove tool to do that

Will the google dissolve tool be helpful?

There is 6 Ways to Recover from Bad Links:
1. Wait It Out
2. Cut the Links
3. Cut the Page
4. Build Good Links
5. Appeal to Google
6. Find a New Home

Use the combination of Google Analytics and Google webmaster to check bad links. Ask the web owner to remove them with comment or emails or contatc us.

In order to remove bad backlinks from your website, you need to send webmasters/website owners a mail with link removal requests. If you don't found any response from webmasters, then you may utilize Google Disavow Tools with the help of Google Search Console to remove bad backlinks.

Disavowing links is an important part of any backlink strategy. Disvowing eliminates the backlinks from spam sites.
Go to google webmaster tool:
Create list of links to disavow in a notepad
Go to Google Disavow links option, select the domain you want to upload to disavow file and then click on "Disavow links"
The deleting doesn't gets instantly but it will take months to disavow.