yes the kindney box has to come out; they are not bolted or anything; they are simply pushed in

might be a little easier to get out of you have the car on a ramp

it will come out, its probably just tight, you shouldnt need to take the inlet off to do it!!

twist; wiggle and pull will normally get it off; you can be pretty brutal with it as i very much doubt you'll do any damage to the block

if that dont work; from underneath twist the kidney box out and then with a bar tap it up