To download and install HP 7858 printer drivers, visit the HP support website and locate the drivers section for the 7858 model. Choose the appropriate operating system version. Download the driver software and follow on-screen instructions for installation. Connect the printer to your computer via USB or ensure it's on the same network. Once installed, the computer should detect the printer, allowing you to print documents and manage printer settings. Regularly updating drivers ensures optimal performance and compatibility with your system.