Have you checked the manual?
http://www.nicoclub.com/FSM/M/2007_M45-M35/ei.pdf (Page 16)
CAUTION:
Apply protection tape around outer circumference of front grille (bumper fascia side).
REMOVAL
1. Fully open hood assembly.
2. Remove plastic clip from upper surface of the grille.
3. Remove plastic clip from front bumper upper side (convex part).
4. Pull front grille frontward. Disengage upper side plastic clip joint from back of front grille using pliers. (Figure
to illustration A.)
5. Pull front grille out toward vehicle front. (Figure to illustration B.)
NOTE:
Plastic clips of front grille lower are engaged strongly. Strong power is necessary to disengage them. (When it
is not easy to disengage them, disengage the joint of lower side clip using a screwdriver while pulling the front
grille frontward.)