Download the latest SMAPI version from the official SMAPI website or GitHub release page
Close Stardew Valley and any mod managers
Back up your save files and mods folder
Extract the downloaded SMAPI archive
Run the installer for your operating system
Follow the installer prompts to update SMAPI
If prompted, point the installer to your Stardew Valley folder
Replace the old SMAPI files when asked
Restart your computer if required
Launch Stardew Valley through the SMAPI launcher or updated shortcut
Check the SMAPI console to confirm the new version is installed
Update any mods that require a newer SMAPI version if needed