Go to
https://www.dell.com/support/home/us...ini10v/drivers and download the drivers you need. Each one will be an EXE file. You can do this on some other computer (even a Mac.) Copy them to a FAT-formatted USB flash drive. Then on the Mini, plug in the flash drive, a directory window should open. Find the EXE file for the driver you downloaded and double-click the EXE, then follow the prompts.
I suggest that you make note of the EXE file name for each of the driver downloads, as they're not always obvious. Many of them will ask for a reboot after installation.