I have forgotten how to do this enough times that I created a screencast showing how to do it. Also wrote down the steps below.

Sync Github Fork Sublime Merge

  1. Checkout target branch locally (let’s assume our target is “master”)
  2. Expand “Remotes” (in Locations sidebar)
  3. Right-click “upstream”
  4. Fetch from upstream
  5. <enter> or click fetch
  6. Expand “upstream”
  7. Right-click “master”
  8. “Merge upstream/master into master…”
  9. Complete merge
  10. Push to origin