kurjak

Hi guys, i have a problem with my dvr: DVR WATASHI 8 CH WRC105 H.264 I changed the factory password 123456 with a new one, but now i cannot access with the new pass nether the old one. So i want to reset the device but i don't know how. i try to disconnect the internal battery... 24 hours but nothing. only the date reset.... Please help me. Thank you in advance.... Cristiano