It's a two section shaft with a flexible joint and support bearing midway. If you can't nudge the shaft aft far enough to replace the coupling, you'll have to drop the exhaust and heat shield so you can get to the midway support. It should be enough to detach the midway support but mind that the front and rear sections don't separate. For good measure, index the front and rear sections so they go back together in the same orientation. You can have driveline vibration if they're not reunited as they were balanced.

Sixto
83 300SD
98 E320 wagon