Denny Cherry has VB code to release an Azure page or blob storage lease:
Sometimes when firing up VMs or moving VMs from the page or blob store you’ll get an error that there is still a lease on the file. To solve this you need to release the lease. But waiting won’t do the trick, as the leases don’t have an expiration date.
I found some VB.NET code online that with some tweaking (with the help of Eli Weinstock-Herman and Christiaan Baes) I was able to get to release the lease.
Click through for the code.