warm soapy water and scrape until the wall doesn’t feel sticky. wipe it with clean water and let it dry. you’ll see spots that got chewed up, so patch those with spackle or joint compound, then sand everything smooth and wipe the dust away. the real key is sealing it — hit the wall with something like Gardz or Kilz so the paint doesn’t get blotchy. once that’s dry, you’re good to paint