You should have the refrigerants reclaimed right away, the reclaimed refrigerant will be sent in to be destroyed because 410 A and R 22 were mixed. You may not have to change oil, but you can have an acid level test done on the oil from a small sample of your units oil. This is a non expensive test that will tell you if you need to add filter driers and acid away to treat the oil. Deep evacuation is very important before a new charge of 410 A is done on your unit, 410 A is a replacement for R 22 but not as a drop in replacement.