If you haven't already committed your changes, just use git checkout
to move to the new branch and then commit them normally - changes to files are not tied to a particular branch until you commit them.
If you have already committed your changes:
git log
and remember the SHA of the commit you want to move.git cherry-pick SHA
substituting the SHA from above.git reset HEAD~1
to reset back before your wrong-branch commit.cherry-pick
takes a given commit and applies it to the currently checked-out head, thus allowing you to copy the commit over to a new branch.