Step #2: declare the refugees leader your Master of Horse, and that the refugees are Foederati and part of your army.
Step #3: declare every landowner has to give up 2/3rds of their property to your new friends, based on an absurd interpretation of an ancient law about military supply.
Step #4. Traumatic decomplexification. De-urbanisation. Dead people buried randomly in the ruins of public buildings. Give up on the Western Empire and pull back to the East.