Let's find that object or group of objects that you want to edit the metafields of.
Start by clicking the Edit Metafields button in the top navigation menu.
Select the object type that you need from the dropdown.
Search for the title
You can fine tune the search results by either entering the title of the object you're searching for, this is suited to finding specific objects.
Or you can use filters to narrow down your objects.
Select the category of the filter from it's dropdown and give it a value.
You can click the Add Filter button to create another filter and further refine your search.
Click the Remove button if you would like to remove a filter.
After entering your search title or picking your filters click Show Results.
Only matching objects will be returned below.
From here can edit the fields of the object you were looking for and then click the Save button.