How to upload the license file in Multitenant Deployment, NAV 2015
Use Powershell (or Powershell ISE) to to achieve this with Powershell cmdlet “Import-NAVServerLicense”
SYNTAX: Import-NAVServerLicense [-ServerInstance] <String> [-Database <LicenseDatabase> ] [-Force] [-Tenant <TenantId> ] [-Confirm] [-WhatIf] [ <CommonParameters>]
Example: “This example imports a license file that is named “fin.flf” from the current directory into the database that is used by the specified tenant, Tenant1”
C:\PS> Import-NAVServerLicense ‘MicrosoftDynamicsNavServer$MyInstance’ -LicenseData ([Byte[]]$(Get-Content -Path “fin.flf” -Encoding Byte)) -Database Tenant –Tenant Tenant1
Source MSDN msdn.microsoft.com/…/jj672905(v=nav.80).aspx
Administration Cmdlets for Microsoft Dynamics NAV
https://msdn.microsoft.com/en-us/library/jj672916(v=nav.80).aspx