I would strongly advise using the factory tool. The side plate is a very tight force fit over the pins. The tool has a magnet to hold the side plate in place while installing it. The factory tool forces the side plate on just the right amount. This will prevent it from binding. A movable mandrel in the tool is then turned and is used to upset the end of the pins. When done, you might never find where the peening was done except for the fact that the master link is a different color!! Some Benz parts houses loan out this tool.