Changing Rims/Tires on a Diablo

This weekend I'm planning on changing back to the OEM rims and tires. I understand that I should not jack up the car one corner at a time. I found a reinforced steel piece under the rear drive transfer case and wondered if lifting the whole rear end at once at this point would harm the car? Where and how should the front wheels be done? Windows and doors opened? I'm open and confident you experts can help me!!

 

The prior owner is getting the manuals for me. I do not have them right now.