Cam chain replacement

Hello all

I have an 850 Mk 1 (1973) and my question is, is it possible to replace the timing chain by just slackening and removing the tensioner or will I have to remove the sprockets and chain as a complete unit?

I am not planning to do any other work on the engine and was hoping to not disturb anything else as the rest of the motor is fine.

Thanks

Sprockets will need to come out with the chain.

Thanks, deep down I suspected I might have to do that

Not that you would be so inclined, but the po of my unit had a master link. It fell out, thank god I was idling at the time in my driveway. Bent a valve just the same. To say the least, this will not happen again.