1. 
2. Click Relocate in the warning message (see 'Relocate Link - Updating URL' screenshot below). Note that if the remote application for an application link cannot be reached by your application, the 'List Application Links' page will display a warning message (see the 'Relocate Link - Warning Message' screenshot below).
3. Enter the new URL for the remote application of your application link and click Relocate.
4. You will need to confirm the relocation, if the new URL cannot be contacted. Otherwise, the application link will be updated.