Head Replacement Pro. is one new professional head replacement tool and we also call this kind of head tools as hdd head combs. They are mainly used to separate the heads and swap the heads. For platter swap, you need it too because you need to remove the head stack first before you can exchange the platters.
HDD Head Replacement Tool Kit http://www.dolphindatalab.com/product/head-replacement-pro/
Head And Platter Swap Pro.Standard http://www.dolphindatalab.com/product/head-and-platter-swap-pro/