Some more tips.
Install newnigma2-lean-dm800se-v4.0.12---ramiMAHER--.nfi in flash, since it is small.
Format internal hd as ext4 and mount with Device Manager in /media/hdd (just press OK button in Device Manager)
Format usb as ext4 and mount with Device Manager in /media/usb
Download mmboot-dreambox_1.42_all.ipk and ftp to /media/usb and install it with Software Manager.
Start Multiminiboot from Plugins. Choose to install to /media/usb
Reboot
Download OPEPLI-6.2-DM800SE-SIM2-84D-17052018-ParageriaGS.nfi.zip and extract.
Rename the nfi file to OPEPLI-6.2.nfi and upload ton box with ftp. Put it in folder /media/hdd/backup
Start multiminiboot from Plugin menu. Choose Install, from backup and install.
Wait until finished and restart.
Wheen booting choose OPEPLI-6.2