In order to be able to dispose of the assets and fulfill your duties as an Executor, you should consult with a lawyer. Being an Executor brings on much responsibility and you should receive proper advice on what these responsibilities are. Not fulfilling these responsibilities may lead to problems from failing to comply with tax law requirements and lawsuits from beneficiaries.
Probating the estate or obtaining a Certificate of Appointment of Estate Trustee is one of the first steps in fulfilling your duty as an Executor.
You should contact a lawyer immediately. It is crucial to your case to act fast because other parties may apply for probate. This will render difficulty in accessing the assets of the Estate. The assets may have already been disposed of if a Notice of Objection is not filed.