Removing head - quick question

I'm sure this is a no-brainer for some, but this is my first time digging into the top end.

If I'm removing the head with the engine in the frame, does the oil still need to be drained first? And the manual says to "run a wire through the chain" - does that mean I need to run it through the links to immobilize it, or simply run it underneath the chain to keep the entire length from falling down?

Also, does the stock exhaust need to be removed to get the middle gear drain plug out?

 

You need to remove the headers to lift the head, so it might be easier to remove the complete exhaust system.
The wire is to stop you loosing the cam chain down the canyon.
You don't need to drain the oil, but how long has it been in the mill, you might want a fresh start.