Go to Dashboard > Appearance > Elements.
In there you will see an Element Titled: Magazine Grid
Quick Edit that and change its Status to Draft
This will disable it from the front end of the site.
If you want to, you can Delete it, but if you want to add it back in the future i would suggest keeping it as a draft.
You have a cache / optimization plugin or service running on your site.
After making any kind of changes you will need for flush those caches or you may not see any changes.