Hi @giomun ,
Here is a link to the [http://h10032.www1.hp.com/ctg/Manual/c02542102.pdf|service manual] for your laptop. Scroll to p.42 to view the necessary pre-requisite steps and then the procedure to remove the HDD. Just reverse the procedure to install the new HDD.
Also on p.42 you will find the part numbers for HDDs for the laptop. You may wish to consider installing a SSD instead so as to improve performance.
Try various sites such as [https://www.mrmemory.co.uk/memory-ram-upgrades/hp/g-series-notebook/g62-series|here] and [https://www.kingston.com/en/memory/search?DeviceType=&Mfr=HEW&Line=G%20Notebook&Model=66246&ktc_campaign=OEM_HP_UK_Shop|here] (select your exact model number in the model box) to see if this option interests you or not.
Usually the BIOS setting is for automatic HDD detection so you shouldn't have to make any changes to the settings in the BIOS.