/
Simply replace the existing .jar file and restart your server.
You may need to update your language strings since biome formatting changed.
Full Changelog:
https://github.com/Happy-Hop7/RealisticPlantGrowth/compare/v0.8.6-BETA...v0.9-BETA

Powerful Spigot/Paper plugin that brings a new level of realism to the Minecraft flora, allowing you to fine-tune growth parameters on a per-biome basis.