Which one of Days Inn hotel do you mean？As far as I see, there are 2 of it in Luohu District. Both of them are not far from the Luohu port.In my opinion, you'd better take a taxi.
By the way ,have you reserved the hotel ?Maybe you can go and see:www.chinahotels.hk

Mr. Chan, Thank you for your reply. I will stay in Days Inn Hotel (57 Yongxin Street, Jiefang Rd.)near Dongmen. I prefer to take the subway (if there is one from Lo Wu), if not then I have no choice to take a taxi. Any subway from the hotel to Windows of the World? TQ.