Well thank you all. You were all correct. No simple fix. I bought the tensioner/belt/shock and got down to business.
Started Friday night and finished Saturday morning. There is one particular bolt that is troublesome. One of the small 8mm that holds the left most part of the 'y' bracket-near the timing chain.

Turns out I didn't have to remove it, you can swing the 'Y' bracket slightly and the tensioner loosens and drops down.

Make sure to check your shock- at the time it's easy access anyway.

Did find a decent way to hold the pulleys down. Take the old serpentine belt you just took off, cut small 3" sections and place 1 or 2 on 'belt' side of the pulleys, and one other piece on the inside lip of the pulley. Clamp down on it with a vice-grip, and turn the pulley until you can lock it against the engine block or the power steering pump.

At that point, it doesn't take a lot of torque because it locks in place- no slipping.

Thank you all for your help. Saved me some $hundreds on the quote from the local Benz shop. Can't imagine what the dealer would have quoted me.

Happy Holidays to you all.