Google launched Penguin Update, causing many sites to lose vital rankings, visibility, and traffic from search engine. The main factor in Google Penguin Update was to penalize website that has unnatural backlinks profile. So doubtlessly, businesses that were hitted in this update would seek to clean their backlink profile to revert back their rankings.
The backlink audit and removal process is long and quite tedious, but it’s a need of time – you cannot avoid it.
Here is a step by step guidelines in form of Infographics. I hope this helps!