1994 Ls400 Stereo Upgrade

[KELSA]

Hi all, I have a 94 ls400 with the pioneer 'premium (hardly) stereo' and is it true that the amp is actually located in the pioneer head unit??? If so, I assume my only real option is to replace the head unit with a 2nd hand Nakamichi deck, as I would like to keep the conservative looks of the console.

Anyway, I was also looking to replace the speakers (considering their age) with some new pioneer TSG1047 (150w) 2 ways and dropping in a 10" in the back (with some minor deck alterations) including a new amp for sub/speakers. I have found a couple of sites with guides to speaker removal, but was just curious if anyone has attempted this before or has any advice?

Thanks.