Follow the product-specific instructions first. Make a full backup and test on a staging server that matches the advertised platform, Minecraft version, and Java version.
Extract the purchased ZIP locally. Read its license, README, dependencies, configuration, and migration notes. Use only the plugin files intended for your server. Install required dependencies separately when they are not included. Avoid replacing existing configuration without a backup.
When the product requires a restart, stop and restart the server rather than relying on an unsupported reload. For support, provide exact versions and only redacted error excerpts.