How Do You Release Timing Chain Tensioner ??

I have a 1995 318i and I my replacement timing chain tensioner (original M42 type with spring) has arrived. I have read the Bentley manual, and I understand about compressing the tensioner prior to installation...however, the Bentley manual refers to a complete timing chain overhaul, which involves the removal of the timing chain cover...after the tensioner has been installed, Bentley says on page
117-5 #11 "On M42 engines: Release early-style chain tensioner by pressing chain guide against tensioner until it unlocks and expands out."

Well, I am just replacing the chain tensioner, without removing the timing chain cover, etc.....so, my question is:
1. How do I go about releasing the chain tensioner once it is installed?

2. How will I know if the tensioner has, in fact, released itself and expanded?

If the tensioner is not expanded against the chain guide, engine damage will occur, but how can I accomplish releasing the chain tensioner if I can't access the chain guide because the timing chain cover has not been removed?
Any help is greatly appreciated...thanks