Restart your career mode with the same superstar or diva you used. You will lose all your gained abilities. However, there is a downside: You will take longer to gain Resiliency if your attributes are higher, and if you are above 80 overall you will not be able to get Durability. Always create doubles of a CAW or CAS immediately after making them. By doing this you can start over with the unused copy and gain those Resiliency and Durability in a quicker amount of time if you end up gaining unwanted abilities.