I have a 87 300 TD. It takes about 5 minutes to get the "plenum" off. That is if we are talking the same car and part. There are two bolts at the round end that connect to the impeller end of the turbo (10 mm head I think) and two allen bolts at the intake manifold end (5 mm I think). It looks like this would come off with the TO mod for access. There is a big o-ring at the round end that is about $15 at the dealer that should not need replacement, and a simple gasket, I don't recall the price, at the manifold end. You don't state your reason for asking this question. The TO mod should be absolutely free, including a courtesy car, even if you are a first time dealer customer. Hope this helps. If you have a W123, I can get some help for you tomorrow.