ASK: best way for grand parents pass their RMB to grand sons in

Grand parents have 1-2 investment houses in China and some RMB. They have enough pension for their retirement life, and strongly insist to sell houses and give it to grand sons before they passed away. Question: what is the best way to transfer their assest from China to US?

Open an account under grandsons' name(s) and receive RMB/USD gift from grand parents? Any tax issue? Or 'trade' their houses in China to a house in US (seems to be a good trade at this point), so they can enjoy living close to (grand) children (after getting green cards), but again, any inheritance tax issue?

Thanks