1. Remove the applications brought by Application Manager from your AM for WSUS console. Remove all the installation approvals doing it the other way around like it is done in the following article. After doing this, any applications brought by AM will not be published to WSUS.
2. Go to Control Panel\Programs\Programs and Features, select Recast Application Manager Integration Client and uninstall it.
4. Terminate the AM for WSUS service by going to https://am.recastsoftware.com Administration - Services.
Make sure that you have a plan for updating or removing the AM supported apps from endpoints. All the applications distributed with AM service have their built-in update system disabled. This means that if you have no other tool or method to update the apps they will not get updated.