It is possible to change disk type for your Azure Virtual Machine. However, conversion requires a restart of the virtual machine (VM). Because of this you will need to plan for downtime during this conversion. Information about this can be found here.
If you still have questions, please let us know in the "comments" and we would be happy to help you. Comment is the fastest way of notifying the experts.
If the answer has been helpful, we appreciate hearing from you and would love to help others who may have the same question. Accepting answers helps increase visibility of this question for other members of the Microsoft Q&A community.
Thank you for helping to improve Microsoft Q&A!