He should be able to take it back to court & represent himself, I am pretty sure?
I'm not sure how it works now but when we were going through this years ago I lost my legal aid & ended up representing myself.
It might be worth doing if the orders are new & she's already not complying...

ETA - I think also you can arrange for police assistance. As in, he can turn up there with the police & they will assist him inhaving her comply with the orders, at least that's what we were told but again that was years ago.
I don't know that this would be the best way however, not very nice for the kids & really I think the very last resort.