This web page at purinfotech should help with that. As for drivers, I assume you had Dell Support Assist installed. If you reinstall SA it will do that for you  or you can manually select and install those drivers. Keep in mind that Windows 10 will also install required drivers but you may need Dell chipset drivers or other drivers that may not be auto installed.
I have just taken delivery of a Vostro 3910 with Windows 11 Pro pre-installed.  I want to downgrade (uograde?) to Windows 10 Pro.  I believe that the embedded Windows 11 Pro activation key should work for Windows 10 Pro.  What steps would I need to follow and am I likely to encounter any problems which I should know about in advance? In particular, can I make a bootable USB flash drive on my existing Win 11 setup, and where can I obtain a Win 10 Pro ISO image for the fresh installation?  Can I burn the ISO to a DVD, boot from the USB and then install from the optical drive? Will the installation process find all the Dell and other drivers that are currently installed for Windows 11?
Vostro 3910 - Downgrade to Windows 10 Pro?