Deleting old TM back ups
I'm wondering if there is a simple way to delete old TM back ups to an external HD that is not close to being full and simply starting over.
Is it possible in Finder to just select all of the old backup(s) and move them to Trash, then empty the Trash? The postings I have read lead me to believe it is not that simple. The external HD is not partitioned, and has no other data on it except for the WD tools that it came with. I've also read that I could just delete the "last" ("latest"?) backup only. Does that accomplish the same as if all old backups were deleted? To be safe, wouldn't the free space need to be zeroed out as well?
All too confusing for a non-Geek! Help!
iMac, OS X Mavericks (10.9.2)