BMW Repair: 1992 bmw 525i exhaust, rear muffler, exhaust hangers

Question
I have a 1992 525i bmw with what I am assuming is still a stock exhaust.  Only the rear muffler is bad.  Can i just replace the rear muffler with a Bosal or boyson brand muffler or do i have to replace the rear and front at the same time?  What is the ansa brand used for?

Thank you  

Answer
you can replace just the rear section, thats actually how it comes from BMW. with an aftermarket exhaust, you'll measure where to cut the old exhaust and then most likely use the sotck exhaust hangers. It should come with a clamp to hold the 2 sections together and seal the exhaust.