Please make sure you have a full backup before starting this procedure.
1. Tools>Define Financial Year>Define/edit year
2. Use + on right to add the new year. You will probably want to choose calendar year.
3. Untick the order book open option and tick copy service term mappings if you want to use the existing ones for the new year.
4. You also need to define salary periods Tools>Define Financial Year>Define Salary periods use + on right , then choose the new year and save.