International connection transit procedure Malaysian to United Airlines in Shanghai PudongT1

I am arriving on Malaysian Airlines (MH) in PVG then connecting to ORD (USA) with United Airlines (UA) in 2.5 hours. I was told I will need to get boarding passes printed for the UA flight in PVG. Where do I go for this? Do I need to exit immigration to do this? Is 2.5 hours enough time? Thank you.