Forget about the password fix request, I figured it out, but next - I'm trying to split my main partition but get this error pop up, I thought I was doing it by this 130 GB Loop Device as you can see in the left side index but I guess that is wrong. These are the steps that I'm seeing start to failure. What am I doing wrong? (please see attachments) thank you

Split Drive 01.jpgSplit Drive 02.jpgSplit Drive 03.jpgSplit Drive 04.jpgSplit Drive 05.jpg