How easy is it to have a custody order changed in Virginia?

My friend's ex is seeking to have their joint custody agreement changed to sole custody? The only change is that he has remarried. She has always been the primary caregiver, even before they were divorce 2yrs ago. She was a stay at-home mother. She is now in nursing school.How easy is it to have a custody order changed in Virginia?Usually the courts will side with the party who is more fit for the child. Persuing this avenue is a two edged sword, and must be very well thought out or it could back fire on the party who is trying to change the custody agreement. For example: Someone who has joint custody sues for sole custody could end up with no custody, and get visitation rights, and end up paying more in child support. So, tell your friend not to worry, unless the ex can prove that he is better equipted to take care of the child, he won't get squat. If your friend isn't a pro-per legal expert with knowledge about court procedure, filing motions, and family law, then it would be smart to hire a good family attorney with lots of experience.