django 1.7 migrations -- how do I clear all migrations and start over from scratch?

So the step-by-step plan I outlined in my question does work, but instead of deleting rows from the south_migrationhistory database table, I had to delete rows from the django_migrations database table.

The command is: DELETE FROM django_migrations WHERE app='my_app'

Once this is done, you will be able to re-run your migrations from scratch.

I just wanted to put all the steps into a command format:

NOTE: The commands below are pretty destructive, it is a means to start from scratch as the OP asked.

After a comment from mikeb I thought to add this line:

PRE - CHECK WHAT FILES YOU WOULD DELETE

find . -path "*migrations*" -name "*.py" -not -path "*__init__*"

Then, adjust the command in step 1 to one that works for your dev environment.

1. remove all the migrations from all the apps:

find . -path "*migrations*" -name "*.py" -not -path "*__init__*" -exec rm {} \; # make sure to be in your projects path

2. recreate the whole database:

sudo -u postgres bash -c "psql -c \"DROP DATABASE rootedin;\""
sudo -u postgres bash -c "psql -c \"CREATE DATABASE rootedin;\""
sudo -u postgres bash -c "psql -c \"GRANT ALL PRIVILEGES ON DATABASE rootedin to vagrant;\"" # vagrant is my current user

3. get your db up to date:

python3 manage.py makemigrations
python3 manage.py migrate