To my knowledge i found that v can't remove the "ALL People" and "Groups"
from the
Quick Launch.
***(If you find the solution means let me KNOW)

If v want to remove the members of Groups from the quick launch means we
can do this
as follows:

Click the Group-----> Settings -----------> Edit Group Quick Launch
---------> From there
you can delete the unnecessary group names and click ok.

Well, you CAN remove "People and Groups" from the quicklaunch  of
the main site, but you can't remove "All People" from the quicklaunch of
"People and Groups" (is this confusing) without removing the
quicklaunch altogether, which I have considered doing. I am waiting for
the next wss version.