Quick and dirty way: Just swap cards and boot up. Win will load the correct driver for the new card from the previously installed Nvidia driver database the old driver used, and have you reboot to load the driver.
Clean and proper way: Download the new driver from Nvidia. Use an uninstall pgm like
DDU and run it form safe mode. Have it uninstall the old Nvidia stuff. Shut down, swap cards. Reboot and install the downloaded driver.
Physically installing the card is as easy as unscrewing the rear bracket on the old card, release the PCIe slot locking lever, and remove the card. Put the ne wcard in the PCIe slot and screw it down.