That particular Tool is made for use with a Hydraulic Press.
As previously stated there is a really good writ up on that JTC Tool
Don't remember which of the below it is in. Do a Post Search for JTC and see if that narrows it down.
DIY Links by Parts Category - PeachParts Mercedes ShopForum
PeachPartsWiki: Do It Yourself Articles - Mercedes Vehicles
This may be the one I was thinking of
Write up - Ball Joints & Lower Control Arm Bushings & Tool Review (PICS!)