I am about to remove the cam chain cover on my '91 16V for inspection and don't have the "special" BMW tool to release the tension in the chain tensioner. Are there other options? I have searched here and cannot find any info on alternatives. 
Can wise and experienced ones advise best procedures for this task. 
Thanks

You could just cable tie it so it won't expand any further and unbolt it. Once you've figured out how the mechanism works you can reset it and bolt it back in. Take a good look at it as it comes apart. Warning... springy bits inside..... oh sh!t. Where'd that go!

Why do you need to release the chain tension? What are you inspecting? Chain/guides or are you replacing valve shims. You don't need to release the chain tension to check valve clearances.

Cheers

I wish to remove the cam chain cover and hall sensor cover to restore and paint as part of a K1 restoration. My 8V motor is straight forward and the K12 is also simple but the 16V is more complicated. 'corse I could just pull the cover off and pick up the pieces afterwards... 
BTW PM sent re K1 tank bag

Hmm....should have read more closely...did see camshaft chain and special tool...
and was thinking locking tool.
But what makes it so more difficult to remove the cover on a 16V compared to a 8V?

Kiwi... You can remove the cover no probs but crank and valve covers will need to come off first as well as the timing gear. This thread has info about that. There's no gasket available anymore for the timing chain cover so just use some Permatex. I use the Black one.
Probably a very good opportunity to replace timing chain and guides if you think they might need doing. It really won't take long if you have it down to that state anyway.

I have the bag here for you.

EDIT: After you remove the timing plate and then the rotor off the end of the crankshaft you will be able to remove the timing chain cover. Be careful how you do that as there is a seal located in the cover itself which seals over the end of the crankshaft.