2.0 6 cylinder 2000 differential/ drive train clun

Hi! New here! Just got a bmw z3 roadster (2000) 2.0 6 cylinder so I think e36? Various things need doing. One of which is the well known clunk in the back. So either diff, half shafts, or uj potentially or all of them. Car only done about 76000 miles. Looking for advice on diagnosing the...