Remove tags from a single item: Go into the details item view and click the cross by the tag.
Remove tags from multiple items: Click “Bulk actions” in the eXplore view. Select the items you want to remove tags from, and then click “Remove Tags”. Choose which tags to remove and press “Remove selected tags”.
Remove tag/s from a collection: Open the collection in collection details view, and click “Edit Collection”. In the opened window - remove the tags by clicking the cross by the tag. Confirm the removal of tags by clicking the button “Update collection”.