create us psn

go to settings > app saved data management > saved data in online storage > activate 2 day trial

https://store.playstation.com/#!/en-us/games/guilty-gear-xrd-rev-2-demo/cid=UP1024-CUSA07837_00-GGXRDREV2USPSPLS

sign in here with account

add it to your list

click download to ps4 and it will auto download to your ps4 if its turned on