If you cannot reach an out of court resolution, then you may have to start an application to ask the Judge to make an order determining the issues.
If you have an existing order for custody, access, child support, and spousal support, it may be necessary to vary or change that order. To change the existing order requires a Motion to Change.
A trial or hearing may be required if during the court proceedings you cannot achieve a resolution. At a trial, the Judge will hear evidence from the spouses, and others, to make a decision.
Motions may be brought to allow you to ask for temporary relief for such issues as custody, access, child support, and spousal support until the trial is heard.