If you are eligible for a divorce it is a good idea to obtain your spouses consent.
You will need a form called a Divorce Petition. If possible it is a good idea to obtain your spouse's prior consent to a Petition being filed as this may help to keep things amicable throughout the proceedings. Your solicitor may be able to reach agreement over the form the Petition should take.
If you have children, you will also require a form called Statement of Arrangements for Children.