Well just take the train up to Kyoto station and from the station it is a easy walk to the hotel. There is two trains: the fast airport connecting one or just local one. local one is much cheaper and it is not that much slower so I recommend taking the local train.
Please correct me if i am wrong. Your question is " how to get to the hotel from Osaka?".
Well i simply took the 7 days JR Pass. This pass allows me to travel anywhere via JR trains for free. Technically its not free, i have paid for it. If i am not wrong, it can be applied from online. I got it from a locally from JTB from singapore.
Get an answer from Hotel Keihan Kyoto Grande staff and past guests.