Revert from development to stable release

I was using the testing repository. Would you let me know how to revert to stable? Thanks.

If you have followed the current suggested mode for testing (via /etc/apt/sources.list.d/osmc-devel.list) then this normally should happen automatically.
You can check the content of /etc/apt/sources.list.d/osmc-devel.list, it should either not exists or be empty.

cat /etc/apt/sources.list.d/osmc-devel.list

Thanks for that.

The development repository is deactivated after two weeks by default.