I going through and replacing the coils myself, but I have a few questions.
The coils are from Courtesy Nissan, but the new parts are slightly different
than the original ones that were in the car.

There's a black rubber 'hose' at the end of the old front coils (which I
assume slips over the spark plug), where the new coils only have a small
piece of clear green hosing that's barely long enough to cover the contact
end of the coil; do I transfer the old rubber covers to the new ones
(assuming I can pull it off the old coil)?  I also went ahead and ordered
the rear coils as well; the existing coils have an extention rod at the ends
of them, which I assume is to reach the spark plug. How do I take those off?
The extention 'bar' just spins around at the base of the coil. So do I force
them off?