Well, I am a DIYer, but not onsome things in a Benz. When you screw up in a Benz, its MUCH more expensive than the old cars I have driven. Oil changes, head cover gaskets, the stuff you cant screw up on is the stuff I do.
If it would have been a timing chain in the Boat(the buick listed below), I would remove the radiator, fan, waterpump and timing chain cover and be done with it. I have never worked on the internals of an engine with an OHC. I also dont have the money to replace stuff I break.
I have looked at the "replace a TC in a M116 before at http://www.pindelski.com,
so I know it can be done myself. Its just one of the few things that I dont work on, like the other things that one could screw up on that turns your car into a paper weight, or, God forbid, a death cart (ie brakes). If it involves more than a pad or rotor change I dont do it. (yes, that involves bleeding. I cant bring myself to do it, because I am afraid that I will screw it up.)
Anyway, thank you all for the advice and help you have given me.