Regular vet visits to monitor the progress. It took three months of intensive medication and monitoring for my bun to recover from head tilt. You need to panacur (or Lapizole) your affected bun and any other rabbits you have that have contact for 28 days. The head tilted bun will need pain med/anti-inflammatory to reduce the head tilt. If the head it tilted badly right over then other medication will be needed.
You also have to montior as other illnesses can be brought on from the head tilt - if the head tilt is due to EC, then your bun could suffer cataracts.
Your vet will explain better all the options and tests needed to be done.