Basically, what I’m trying to do is get rid of commit 5581ecb023a9, which was created in the merging process of two branches. What I’m trying to get to is everything in one straight line.

So far I’ve tried to do git rebase -i 5581ecb023a9 following some previous posts, though it doesn’t show the actual 5581ecb023a9 commit. I tried git rebase -i a19ba5850a20 which also doesn’t show the 5581ecb023a9 commit.
Any idea on how to get them all into a line?
Thanks in advance.
To do this, you need to rebase against a commit from before either side of the merge diverged from their common ancestor – e.g.
git rebse 8fedb6