Move Azure website between App Service Plans
The original accepted answer is more than a year old. In Azure world, that's an eternity. The "Change App Plan" button in the Azure Portal is no longer present it appears (as of 2016-06-17), so I'm throwing in the Powershell command I needed to use in order to move a Webapp to another App Service Plan.
Set-AzureRmWebApp -Name <webapp name> -ResourceGroupName <resource group name> -AppServicePlan <new app service plan>Set-AzureRmWebAppSlot -Name <webapp name> -Slot <slot name> -ResourceGroupName <resource group name> -AppServicePlan <new app service plan>
The option "Change App Service plan" has been moved to the APP SERVICE PLAN menu.
Yes, you can do this from the Web app blade in the Azure portal. You have to expand the toolbar though to see the option. See below.
