For this tutorial step, we have prepared a repository with some ready made commits to speed things up.
You can download the repository here.
Go to the downloaded "stepup-tutorial/tutorial6" directory and examine the history of this repository. It should look like the following.
We are going to amend the commit with the message "append description of the commit command".

Pass in the commit you wish to amend when calling rebase -i.
$ git rebase -i HEAD~~
Your default text editor will open listing commits from HEAD down to HEAD~~ as shown below.
pick 9a54fd4 append description of the commit command
pick 0d4a808 append description of the pull command
# Rebase 326fc9f..0d4a808 onto d286baa
#
# Commands:
# p, pick = use commit
# r, reword = use commit, but edit the commit message
# e, edit = use commit, but stop for amending
# s, squash = use commit, but meld into previous commit
# f, fixup = like "squash", but discard this commit's log message
# x, exec = run command (the rest of the line) using shell
#
# If you remove a line here THAT COMMIT WILL BE LOST.
# However, if you remove everything, the rebase will be aborted.
#
On the first line/commit, change the word "pick" to "edit", then save and quit. The following output will be displayed and you will be checked out to that commit.
Stopped at d286baa... append description of the commit command
You can amend the commit now, with
git commit --amend
Once you are satisfied with your changes, run
git rebase --continue
Open the file sample.txt and make the change as shown below.
Git commands even a monkey can understand
add: Register a change in an index
Commit: Record index state.
pull: Obtain the content of the remote repository
Use commit --amend to make the change.
$ git add sample.txt
$ git commit --amend
You will now need to execute "git rebase --continue" to proceed with completing the rebase process.
$ git rebase --continue
While running a rebase on your current brach, you
may run into conflicts in your changes. In that case, you will want to manually
resolve those conflicts, then run "add" and "rebase --continue". You would only
want to resolve conflicts at this point, and there is no need to issue any new
commits.
If you would like to stop rebasing however, you can call
"rebase --abort" which will revert and exit the entire rebase process.
If done correctly, the commit should now be successfully amended.
In cases where you specify "edit" on more than a single line when calling "git rebase -i", you will be prompted to amend each of the commits one at a time.
ORIG_HEAD points to the original commit before rebase actually takes place. This may come in handy especially when you accidentally issue a rebase. You can restore the previous history state by executing a rebase to ORIG_HEAD.