Leaving insider program depend on which build you have installed.
If you have Canary channel build 27xxx then you have to do clean install of releaed version 24H2. Make sure that you take backup all files you wan to keep before doing clean install.
If you have build 26xxx then can go to released versio without clean install with these steps:
- Download Windows 11 ISO https://www.microsoft.com/en-us/software-download/windows11
- Open Regedit and delete HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsSelfHost key and restart.
- Mount downloaded ISO (double click or right click and select mount), run setup.exe on mounted image to start in-palce repair which will reistall 24H2 without deleting your files or apps.