Swap '95 3.4L V6 for 3.8L V6?

Hello. I have a 1995 Pontiac Firebird (not Formula or Trans AM) with an automatic trans and a 3.4L V6 (160 hp). I would like to swap it for a 3.8L V6 (200 hp). I've been told I can do it without any major modifications and I've been told I would need to upgrade the tranny, pcm & rear axle. Could you please set me straight. What specifically would I need to do to complete this conversion in detail. I want to make sure I do this correctly. Money is not the issue. Just want to do it right the first time.
Thank you so much.

Marlon