You definitely need special Rolex case back opener. Without it your watch will be locked forever. Rolex cases are so tight, that even when special opener is used, you will need quite strong arms to open it. Rolex case openers sometimes sells on ebay, but they are never cheap.

You shouldn't need to open the back to get the date of this watch! Rolex serial numbers are engraved between the case lugs at the six o'clock position, then its just a case of Googling Rolex reference numbers to find a list.