I haven't done a 300E but I've changed them in my cars and I expect the procedure is the same.

Yes, you remove the six bolts, and yes just replace it with the new one, but here are a few things to look out for.

The new flex disk has a front and rear facing side and the links have different hardness. So make sure you install the new one with the correct side facing forward and the correct bores bolted to the transmission (the double links must be under tensile stress). The double links can easily be determined by bending the flex disk. There is considerable difference in the stiffness between the double and single links.

My flex disks have had a short protrusion in the rubber that indicated the transmission side and a bore that bolts to the transmission.

Pay close attention to exactly what bolts attach to the transmission and which ones attach to the drive shaft and where the washers are. My bolts are of different length and the washers are not in the same place on all six bolts.

If there is ANY play between any of your old bolts and the bore on the new flex disk, you must replace the worn bolt. If you don't, within a few months, the bolt will look like an hour-glass and you'll be going through this again.

I hope this helps.

Cheers,