Changing consent order

My partner’s custody of his son is determined by a consent order that includes restraining order between him and the mother and extremely limited visitation. Over the past year, the noncustodial parent has been present at each visit, paid child support on time, brought gifts, and generally complied with the order. Frequently the custodial parent has skipped visits, deciding not to come at the last minute. There are no mental health issues, no abuse or neglect (actual or alleged). But given the inflammatory nature of the separation, it made sense to sign the consent order in order to continue his relationship with his son, who was very young, rather than continuing his absence from his son’s life while waiting for court.

But now a year has passed, both parents are in more stable situations, the noncustodial parent has made every effort to prove he’s responsible but the custodial parent, thanks to the consent restraining order, they cannot communicate. So he’ll have to file a motion to modify custody, and it seems mediation would be the best option (although she can refuse because of the restraining order) - really he just wants to be able to communicate with her regarding their son, and he wants to coparent.

My question is: during the time between now and the hearing and the motion, what can he do to prove that he is a fit parent? Does evidence need to be included in the motion about his employment, his house, is car, his sobriety? Are these things included in the motion? He has no idea what her arguments will be but is concerned that she’ll be able to refuse everything thanks to the restraining order, despite the absence of abuse, neglect or violence.

He needs to have enough facts in his motion to constitute a substantial change in circumstances, but he doesn’t need to put all of his evidence in the document. The evidence presented will depend on the facts of the case, but almost anything can be relevant if it shows why a change of custody would be in the child’s best interests.