Download Install.cls.xml (from folder in repository or releases page) into Caché manager directory.
Run in terminal (any namespace):
do ##class(%Installer.Installer).InstallFromCommandLine(##class(%File).ManagerDirectory()_"Install.cls.xml","Namespace={Namespace},IP={IP}")
where:
{Namespace} is a namespace you want to install to. If it does not exist it would be created automatically. If it does exist only MDX2JSON package would be overwritten.
{IP} is an optional parameter of address of your server (with port, if required). For example "45.45.45.45:57776", "mycacheserver.com". Required if you wish to use webhook functionality.