Need advice...exhaust problem!

I noticed exhaust coming from under the hood of my '87 300D the other day. I trace the leak to a flexible flange that connects the two manifold(exhaust) pieces together held by circular band clamps.It is CRACKED!
I have a parts breakdown book that shows a metal sleeve inside of the flexible peice.My question is: Do I have to remove 1/2 of the exhaust manifold to get the sleeve and flange out to replace them.I loosened both clamps and could spin the flexible peice but it seem to not want to come away from the manifold.Any tips on removal and where i could purchase these items would be helpful.
TIA. Joe.