how are people disavowing backlinks in 2026?

Mostly they aren't, and that's fine. Google says it ignores most spammy links on its own. The disavow tool is really for when you have a manual action for unnatural links, or you know you bought or built a pile of bad ones. Random junk domains pointing at you? Leave them. If you do need it, it's a plain txt file with domain: lines, uploaded through the disavow tool for that property. Be conservative. Disavowing links that were actually helping you is the easy way to make things worse.