Klimfilt

Hi guys, i'm thinking to change my comand to NTG 2.5, because my ML 06's is with NTG 2.0 US Version and it doesn't work in Europe (navi and some FM stations on radio) I've read a lot and i'm a bit confused of what i need to do/buy to do it right. I will buy NTG 2.5 from someone crashed ML or GL and if it had a anti-thieft code i will know the VIN. But do i need to buy new GPS antena or i can use the old one? And i've read that NTG 2.5 has a built-in a bluetooth so if i don't have a module or cradle and wired cables of the old one, can i connect my phone to the new comand and use it without cradle? My car doesn't have Harman Kardon. Can somebody tell me what i need to do step-by-step because i'm totaly lost.
Here is my car with VIN decoded: