[yelcab1]

That is a part that you can remove then replace the seal and the aluminum gasket. However, you need to drain the oil from the engine or there will be a big mess. More importantly, 9 times out of 10, the now-loose cam chain will not move out of position while you are doing this work, but that one time out of ten, it will move and you will be in trouble. To totally prevent that, you need a cam locking tool. You also need a big wrench and a big torque wrench.

Frankly, if you had to ask what it is, this is probably not a place to start learning. But, it is your car and you know yourself best. Dive right in if you think you can handle it.