fraenkn

I have a DVR DAHUA HCVR 7208A-V2, it is installed, and working fine, the problem is i forgot the password i set to it, so in case of a problem I cant log into it or check the cameras, to set it on my new phone. How can I reset it or something to the default. The other Accounts are deleted. Remove BIOS battery has not helped. PLEASE HELP ME Thank you ----FINISHED----