About 10 threads down is a guy asking the same question
You'll need the removal tools to remove the unit...but it can be done with a pair of coathanger wires bent into 2 "u" shapes, just put them in the holes and push them outwards while pulling the unit out....if that makes any sense lol.
Either buy an ISO wiring harness for the VY or wire the unit up manually...the wiring diagram is on the top of the stock unit.
You'll also be needing a VY facia kit, available from most car audio stores etc.
The kit will just "pop" into place, do this once youve got your wiring sorted then use the cradle the aftermarket unit came with to mount the head-unit (i think this is how its done or do you use the mounting holes in the facia kit...damn it cant remember now)