How to remove a Shimano Quick-Link? I'm currently repurposing an old frame and replacing the drivetrain. If possible I'd keep the old 7 speed drive train the bike had together in case I ever find a use for it. The chain is an HG40 quick-link. There's plenty of info online about joining chains with quick-links but little about breaking and reusing them.

Is there a trick to the quick link to separate the chain so it can be easily reused or do I just need to break it with a chain tool? 

The install Tech Doc can be found here.
This is a different link than the Sram type of links. Here is a link to the directions I found that includes the HG-40 Quick link. Hope this helps!

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Chain/SI_0034B_001/SI-0034B-001_13_v1_m56577569830625422.pdf