Doing both the lower and
upper grilles took me most of one afternoon although most of the time was
spent waiting to put progressive coats of paint on. First I purchased
some galvanized mesh from Home Depot (under $5) and then bought spray paint
from Wal-Mart. I used Krylon 1401 Bright Silver spray paint since
it matches the body color of my car almost perfectly and I aslo picked
up a can of Krylon Crystal Clear clear spray paint. Since you are
working with metal a can of rust-proof primer also comes 
in
handy.
After all the money was spent (less than $20 total)
I cut some cardboard into the shape of the bottom grille, used it as an
overlay on the mesh, and cut the mesh to shape. Since the top grille
has more of a contour to it using cardboard was too tough so I used timfoil
instead. Fold the tinfoil over about three times to add stiffness
then just tape the foil to the mesh and cut out the shape. I cut
out a hole in the mesh so the Honda emblem could show through. After
the mesh was cut all that was left was 2 coats of primer on each side,
3 coats of silver, and about 4 or 5 coats of 
clear.
The clear coat makes bug guts come off the grill much easier.
To attach the grilles I used 20 lb test fishing
line and just tied it to the plastic pieces running behind the new grilles.
It's worked good so far but if I have to retie it I plan on drilling holes
in on the perimeter of the bottom grille and then using zip-ties.
If the top one comes loose I'll probably retie it since there isn't the
room to drill holes and still have a clean looking grille.