headunit upgrade - e46 m3 w/ HK

[blur212]

i know this has probably been asked before and i've been searching for a day. i just want to get it straight. i want to upgrade my h/k system headunit in my e46 m3 to an alpine iva-c800.

i want to know if anything is needed other than the wiring harness and antenna adapter to install the headunit. i have the h/k system in there now and just want to use it for now until i upgrade the rest.
is it a simple plug and play job or are any converters, etc. need for the install. just want to make sure also because i might just get it done because i have to put the brain somewhere and don't really know how to install that. but if anyone has tips or a DIY that would be great. i would like to install it myself.

thanks!

rob.