@BHARGAVP2854 In general once the record is created in a table Primary Key column data cannot be modified unlike other columns data. If you are adding manually its better to create new record and remove old one. If you are doing through any activity follow these steps.
1. Open the existing record which is 1 using obj-open.
2. Copy all required data of id 1 to a temporary page , assign new value to id .
3. Save temporary page data and delete the previous one.
So, only one record with updated id and previous data will be present in the table.