Engine conversion Audi Coupe from 2Ltr to 2,3Ltr 20 V What has to be done?

Hi guys! Yesterday I asked here because of the high consumption of my 2.0 Ltr. engine and today I get offered an accident Coupe with 20V machine for small money.Now of course I am tempted to install the engine in My Coupe.It is everything except the air mass meter and the air filter box.When the beetle told me that I can have the whole technology for 250 Euro during self expansion I did not think for long.The engine has already 273 Tkm down abe Now the question is how much effort is it to make the conversion, is there stress at the Tüv and fits the Agregat 1 to 1 in my car? Can someone give me some tips. Would be grateful for any help. As said exhaust, motor, gearboxes, cable harness and control units are there. I also get the brakes.