Yes it is done by credit hours. Your cumulative GPA should be listed on your transcript. I am in the same position… applying to Law School with bad marks from DE courses. I was shocked to find out a month ago that my chances of getting in have been obliterated because of college courses taken at the age of 14! There is unfortunately no way to remove these courses. I have looked into legal avenues, forgiveness policies, and talked to dean of my dual enrollment college and current college. You can apply for Texas Fresh Start if it has been 10 years since your bad marks. They will erase your record from the semester exactly 10 years ago and prior to. It doesn’t matter if you’ve received your degree or have never attended a Texas school before. They completely remove the classes from your transcript. I called Texas A & M University, who confirmed that all of this info is true.
As a side not to all those reading this- Unfortunately, Law School and Med School will require you list ALL grades ever received. Although, Texas has their own system for collecting and sending your GPA and MCAT scores compared to the rest of the US called TMDSAS, so Texas Med schools will honor the program.