Excellent. They have all of the forms and instructions that a parent needs to request a change in custody available for free. He doesn't need a lawyer to file them, although he could look into paying someone to review the forms before he files if he wants - that would cost less. Another option might be to see if there's a law school in the area with a family law clinic, but he should look through the papers first (linked below) to see if he feels confident submitting them himself.
He has to be able to establish either that it's been 6 months since the last order was entered OR that the child's health is in danger. If the mother's refusing to give the child necessary medication (or forgetting), he's going to meet the latter requirement.
Here are the forms and instructions. It's all pretty detailed, so read through it carefully. If you have more questions after he reviews the paperwork, I'm happy to answer them.
He'll file the original paperwork and serve a copy on the mother. She gets a chance to respond, and then a judge will decide whether to hold a hearing (it's likely, in this case). At the hearing, he'll be able to again present his arguments and the judge will decide what's best for the child.
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