how schedule kppp to autodisconnect

Hello, I want to make kppp autodisconnect itself at 6:00 AM. How could I do this? something to do with CRON? Any bash script? thanks for any help a. -- Adagilson Batista Bispo da Silva Bibliotecário FIOCRUZ-Centro de Pesquisa Aggeu Magalhães Fone 81 3302-6524