In order to open this watch you will need a watch opening tool. Those are normally called "Jaxa" style. This is to secure the midframe while you pop up the back. This will require force as there is a rubber seal and the fit is tight.

Remove the ribbons from the PCB marked in the photo

Remove the screws that attach the pcb to the plastic mid frame. You can separate the midframe from the case and access all the components

Screen and digitizer part numbers is marked as WB014ZNM-N00-6D00 MFPC R0.4

Battery is an odd round battery made by Grepow. Part number is ABI403530 360Mah 3.8V . Closest match i can find is GRP4035030, probably with a custom made connector.