Moving a clam, what exactly to cut?

[Shigshwa]

I've attached a diagram of a clam's anatomy for reference.

I read that if you have no choice but to move an attached clam, you should cut the threads as close to the rock as possible. However, I've noticed too that the clams don't exactly always attach to the rocks one thread at a time. There is a fuzzy looking thing at the opening, and it seems like the clams also attach with that entire bundle, and I don't see any single particular thread to cut, or a few for that matter. I believe on the diagram, that bundle is the byssus.

So, if you were to try to detach the clam from the rock by cutting into this byssus as close to the rocks as possible, would anything be damaged? Or is the byssus just a big bundle of previously detached threads?

 

[Yuki Rihwa]

It's just a bunch of byssus thread, I meant a lot if the clam healthy and sat at same spot for months or years.
The area of the thread can cover up to 1 inch (experienced on 6 inches size clam) on hard surface for big clam, it's hard to cut if the clam attach to rock work or tank bottom and even harder if you try to cut the thread while the clam still in your tank since you don't have much room for the operation.
*I read that at some point the clam will loose the thread once they grow big enough and heavy enough to stay at 1 spot without byssus thread to help to them stay in place.
Edit:
I forgot to mention that when the clam closed up, it's tied up all it muscles and it's hard like it got clued on the surface and that make it harder to cut it if the clam in your tank.

 

[hart24601]

I have never had an issue with slipping a razor blade under a clam shell to cut the threads, I just always make sure the clam is closed up tight so the foot isn't down, but ime when they close up everything is tucked in and you are good. At least I have never damaged the clams when I cut the threads, maybe a dozen times give or take over the years.