How to achieve this in Source Tree, Was able to perform this steps from Terminal but need to know how to do it from UI?
Merge conflict
This pull request has conflicts. You must resolve the conflicts before you can merge:
Step 1: Fetch the changes (saving the target branch as FETCH_HEAD).
Step 2: Checkout the source branch and merge in the changes from the target branch. Resolve conflicts.
git checkout Reverting git merge FETCH_HEAD
Step 3: After the merge conflicts are resolved, stage the changes accordingly, commit the changes and push.
git commit git push origin HEAD
Step 4: Merge the updated pull request.