Propagating Amazon Sword

I've got a nice healthy amazon sword in my 2 month-old 55 gallon tank.
It's got two runners or shoots coming off of it, with varying levels of
leafiness. Some of the clumps of leaves have about 1/2 inch roots
coming from them. Regular gravel, fertizer tabs in the gravel, no CO2
but well aerated and plenty of fish, 96 watt full spectrum lamp and 96
watt actinic.

I'd like to plant at least one more sword from these babies, but...

I'm not sure when to do it -- how long should I be waiting for the roots
to get? Since I just have gravel I'd imagine that the new plant needs a
decent root system to do well.

I'm wondering if I should trim off one of the shoots, so that the plant
focuses its energies on the other one?

I also don't know just how to go about doing it. Do I snip off the
shoot above and below the clump of leaves and roots that I want to plant?

Thanks in advance!
--
Jeremy