The Grape Visual Page Builder is a Blesta plugin from the SystemFreaks suite. It is encoded and licensed through the SystemFreaks Update Checker.
Without the Update Checker: download the package from your SystemFreaks client area, upload the blesta_grape folder to plugins/ and install it under Settings > Company > Plugins > Available.
Open Tools > SystemFreaks Update Checker, click Check Now, then click Update next to the plugin. The Update Checker keeps a backup of the old folder and runs the plugin upgrade.
Before you uninstall the plugin, set the client template back to Bootstrap under Settings > Company > Look and Feel > Template when a Grape template is active. The Grape client templates need the plugin files.