Only users with system maintainer rights can use this extension.
Go to the module Admin tools > Grid migration:
What grid elements do i have on my site?¶
Click on click here in the important notice box in the first step. After that the extension analyzes your page and also gives you first instructions.
Migrate grid elements from gridelements layout key¶
Click on Migration form gridelements layout key in the dropdown to migrate all elements on the web page using layout key.
Clean up the database¶
Search in the database for content elements that still use the
SELECT * FROM tt_content where colpos=-1;
In most cases all content elements that had been deleted in TYPO3 can also be deleted from the database.
This step cannot be undone! Make a backup first
DELETE FROM tt_content where colpos=-1 and deleted=1;
Then make a database compare at Admin tools > Maintenance > Analyze Database.