just seeking some information about hooking subs into my stock premium sound head unit in my BA. is it going to be hard to do and is it true that i need to purchase a low level output converter for the installation swell?

From my understanding there are no pre-outs from the factory ICC.
Someone was trying to make a module at one point to connect aftermarket amps to the factory ICC using pre-outs but couldn't filter out interference.

The way to go is to use low level line converters from your front/rear speakers to your amp.

The only other option is to install a second head unit with the amount of pre-outs you require but I can understand why you would want to avoid this and personally i would too.