Tags are managed via the locations they're attached to. To completely remove specific tags from the locator, simply remove them from the locations they are assigned to. This can be done by editing your spreadsheet (if you're using bulk import or the google sheets sync - see below) or via the location management area.
If you're using bulk import or google sheets sync, it is important to remove the tags from the source so they aren't re-uploaded in the future:
Bulk remove tags from locations if you're using Google Sheets Sync
Remove all instances of the relevant tags from the "tags" column.
You can use the "search and replace" function in Google Sheets to speed this up. Simply replace the tag with blank text.
Bulk remove tags from locations if you're using a spreadsheet bulk import.
Export all locations using the export function and remove all instances of the relevant tags from the "tags" column. Re-upload the new CSV spreadsheet.
Most spreadsheet editors have a "search and replace" function that can be used to replace all instances with blank text or a "space" character.