nic-hdl: PA1939-RIPE

Good day, I want to change information for following object: inetnum: 82.147.64.0 - 82.147.95.255 But i don't know Authorisation for org: ORG-Tc5-RIPE and mnt-by: RIPE-NCC-HM-MNT. How i may change information and how get to know Authorisation password. Regid: ru.sibtel.ru NIC-HDL: PA1939-RIPE Best regards, Podworko Alexander