Deezel, I have tried to do this w/o removing the fan or shroud. Take my advice, remove them. Unless of course, you like a challenge. You can spend a ton of time trying to get the belt around all of the pulleys and such. With the fan and shroud out (not a very big job), it's a whole lot easier. Tips: Do the shroud first, hang it over the fan, then remove the fan and shroud. The tensioner should be backed off before you do anything. Remember to realign the tensioner adjustment pointer after the new belt is in place. I'm not sure on the diesel, but I believe the belt should go around the tensioner pully first, then crankshaft, alternator, idler, A/C if applicable, PS pump and water pump. Be careful, it is possible to put the belt on incorrectly. I'll try to get the order and the info on setting the tensioner. (got to look it up).
1987 BMW 325