front only needs the bracket made if you dont have one
when u buy the jspec.. check if it has a bracket which bolts onto the chassis
eg..
bumper support.. theres a L shaped bracket that bolts onto the chassis..
(held by 2 bolts)
so once that bracket is installed on the aus spec.. to undo the bumper u would have to undo the 2 bolts that holds the bracket to the bumper..
(DRILLING REQUIRED TO INSTALL BRACKET ONTO CHASSIS)
there will be 2 markings on the chassis but no hole..
rears, just like the aus spec..
maybe a few more bolts (to hold the bumper skin to chassis)