plastic inner fender has to come off, but be sure to buy all new plastic fasteners! they break or strip out easy. and i did the washer pump seals just because it has to come out and the seals are dirt cheap so i wont have to take it apart again any time soon. the hole saw size is in the instructions i can't remember the size.
I bought the turn signals off of ebay they come off of blister fender pajero, strada L200 and lancer evo 4-7, and there are two types that fit the existing hole a flat one and a bubble one they both come in clear or amber plastic
only buy OEM or OEM replacement they snap right in exactly the way your montero badge does. DO NOT BUY UNIVERSAL!! they are screw on or stick on and will not snap right into place