Open Guest Details
In OYO OS, click open a booking from ‘Bookings’ tab on the left.
Your booking will appear as below. Notice the ‘Edit Details’ button.
View & Edit Guest Details
Click on the ‘Edit Details’ button and you can view guest details as below.
Note : In case of multiple guests, you can view & edit guest details for guests in each room. 
On this screen itself, edit the required details and click ‘Update Details’ button.
Point to remember
When you open a booking, the ‘Check In Now’ button, shown next to ‘Edit Details’, will appear only from the day of scheduled check in and until the check in has not been done.