You can either follow these instructions or contact support:
One can access the Autodesk Subscription Center by accessing the following link:
You will need to log on using your Autodesk user id and password. If you have forgot your password, then choose the link that you forgot your password and use the e-mail address which is associated with your contact information. Alternatively, one can call 1-866-487-8680, then follow the phone prompts.
Customer Support Engineer
285 Kappa Drive
Pittsburgh, PA 15238
Please call Autodesk Product Registration and Authorization:
1-800-551-1490 > Option 1 (English) > Option 2 > (Network)
Asia / Pacific: 65.6735.5688
Europe / Middle East / Asia: 41.32.723.9595
You will need to provide your serial number and ethernet ID of the new license server.
For a Quick-Start Guide on configuring the Autodesk License Manager, please see my post for further information:
FLEXnet License Admin | MSI Cleanup Utility | .NET Framework Cleanup Tool | IPv6 NLM Fix | adskflex.opt Options File | Combine .LIC Files | Disk Space