Replace Non-JBL Nav audio with JBL Non-Nav

Looking for advice on replacing my 2015 Non-JBL Nav audio system with the JBL non-Nav audio system that is in my 2010 Prius. I'm about to scrap the 2010 and I don't use the Nav system or any of the touch screen stuff on my 2015 anyway. I suppose I could just swap out the speakers and maybe install the JBL amp under seat and keep the current 2015 head unit in place, if that will work? Going that route, I assume I'll have to figure out how to tap the JBL amp into the exisiting input and output audio wiring somewhere? Any advice appreciated on that or other aspects of the swap. BTW, I'm not interested in purchasing any third-party components to improve the audio. The JBL system in the 2010 is more than adequate for my needs. The 2015 - not so much. Thanks.