How to reset the admin password on VM on Windows Azure?

There is an option now in https://portal.azure.com/ You need to log in with your Azure credentials. Browse -> Virtual Machines -> Select Your Virtual Machine -> Select Setting on top -> Password Reset

https://portal.azure.com/# > on left, "Virtual machines" and not Virtual machines (classic) > line with your VM > Reset password at bottom of middle column, under SUPPORT + TROUBLESHOOTING > Eureka!

Takes a minute or so.

Actually you can with PowerShell's help. For more details read "Microsoft Azure Virtual Machines: Reset Forgotten Admin Passwords with Windows PowerShell".

Import-Module Azure

$subscriptionName = "Windows Azure MSDN - Visual Studio Ultimate"
$cloudSvcName = "ChangeThisWithYourVMServiceName"
$VMname = "ChangeThisWithYourVMName"

Select-AzureSubscription -Current $subscriptionName
Get-AzureSubscription | Format-Table –Property SubscriptionName
$adminCredentials = Get-Credential -Message "Enter new credentials"
$virtualMachine = Get-AzureVM -ServiceName $cloudSvcName -Name $VMname
    If ($virtualMachine.VM.ProvisionGuestAgent) {
        Set-AzureVMAccessExtension -VM $virtualMachine `
            -UserName $adminCredentials.UserName `
            -Password $adminCredentials.GetNetworkCredential().Password `
            -ReferenceName "VMAccessAgent" | 
        Update-AzureVM
        Restart-AzureVM -ServiceName $virtualMachine.ServiceName -Name $virtualMachine.Name
    } else {
        Write-Output "$($virtualMachine.Name): VM Agent Not Installed"
    }

There is no way to do this now, but you can get the data off of the drive if you need to. Please see the Microsoft answer here: http://social.msdn.microsoft.com/Forums/nb-NO/WAVirtualMachinesVirtualNetwork/thread/92a55a09-19c9-4731-b7a6-2b1a9ea909f7