Welcome to the Q&A Forum

A new client of mine sadly has a TON of terrible links (3800 links from 1500 domains) which are pointing to landing pages that have been created specifically for manipulating engines. Besides contacting these sites and asking to have the links removed the only solution I can think of it to delete these pages and let them 404. Obviously I am not thrilled about that but I'm not sure what else to do. Does anyone have any other ideas for how to clean up this backlink profile? Thanks