WSO2 officially describes the Patch Application Process at page https://docs.wso2.org/display/EMM110/WSO2+Patch+Application+Process
"...The WSO2 patch application process is automated from WSO2 Carbon 4.2.0 release onwards. You can simply place your service pack (e.g., servicepack001) in /repository/components/servicepacks directory and restart the server. To revert the service pack, remove it from the service directory..."