Move a whole branch

Lets say you have a series of changes like this:

Branch before rebasing

And you would prefer that they looked like this:

Branch after rebasing

Since you already know how to move the changes in one commit, you could apply the changes in each of the commits one at a time. That's sorta feasible for this case where the branch has only three commits, but for longer branches that could be a huge pain.

What you'd really like is a way to automatically take the ABC branch which is based on gitfromscratch and redo each of its commits so that it is based on 123. Rebase changes the base of a branch by automatically applying the changes in each of its commits.

How do I rebase?

As usual, in order to change a branch, you must first check it out. Then, you right click the branch which you would like to be the new base of this branch, and select Rebase.

Branch after rebasing