Update Management
New versions of KoLmafia are posted to the GitHub releases page. To manage updates, many members of the community have produced "automatic update" scripts.
Gausie's One-Liner
In a Unix shell (Linux, Mac and WSL) as long as you have curl and jq installed this should download and run the latest version.
curl -fLsgo kolmafia.jar $(curl -fsg 'https://api.github.com/repos/kolmafia/kolmafia/releases/latest' | jq -r '.assets[] | select(.browser_download_url | contains(".jar")).browser_download_url') && java -jar kolmafia.jar