guinea with one long claw

I was informed this morning that one of our guineas has one very long claw. I read somewhere to put a concrete block in the coop. I also read that what someone (from backyard chickens) did for chickens was to use cat/dog nail clippers and clip back the toenail. If it bleeds, put flour on it.

What do all of you recommend?

With chickens i have clipped toenails with small side cutters or wire cutters shouldnt be too much different. If you hold the foot up agains the light you will see where the quick ends and where the extra build up of the nail begins, I would go just a little bit out from the quick myself.
Although maybe claws are different than toenails?
If you do err and cut a little deep it is usually just a few drops and pressure and elevation seems to do the trick.
Anyone more helpful that actually has guineas?
Concrete block is probably a good idea but if one if that much longer I think it should be clipped right away.

Some of my bantams get long toe nails
and I use a dog nail clipper just like
doing dog nails just cut in front of
the quick.

Some of my hens and guineas get long toenails/claws. I always wonder why but just trim them periodically.

Maybe check that the toe itself isn't broken or damaged. Funny it should be just the one.