The answer to 'how to unclog sewer line' is to first try using a plunger or a drain snake to dislodge the blockage. If that doesn't work, you may need to use a sewer auger or call a professional plumber. Sewer line clogs can be caused by things like tree roots, grease buildup, or debris in the pipes.
It's important to act quickly when you have a sewer line clog, as it can lead to sewage backups and water damage if left untreated. Try the DIY methods first, but if the clog is severe or you're uncomfortable working on the sewer line, it's best to call in a professional plumber who has the right tools and expertise to safely clear the blockage.