1: Download the tools.
Second Stage Bootloader
Flashing Tool
Mini USB Windows 2K/XP/Vista/W7 Driver
Image "Nemesis Patch 2.3 SVN090 DM800se Sim2.10 - By vyper and langioletto"
2: DM800se must be set from menu/setup/network setup to DHCP!
3: Connect your 800se with Lan cable and mini usb cable. Windows will try install the new device drivers. If the drivers installation was unsuccessful, then install "Mini USB Windows 2K/XP/Vista/W7 Driver" manually. After successful drivers install you will be reported that new device is example in COM4.
Power off your 800se.
4: Open Sunray Flasher. Tick "With Network" and the "Serial Port" set to COM4 at last fill out the IP settings. And hit the tab "Connect"
5: Power the box on and wait till the box is recognized and the "Flash" tab is dark. Next hit the "Flash" tab and look up "sim2SE_SSL82_110620.nfi". If the flash is gonna successfully u get a notice. After that hit tab "Disconnect" and power off the 800se. Close the Sunray Flasher.
6: Press and hold from front the 800se Standby button. Power the box on and wait till u have on OLD display message *** STOP *** then release the standby button. Now open internet explorer and write there a IP what u see from 800se OLD display. DO NOT USE FIREFOX! You get new window open and down there is "firmware upgrade" hit that. Now add image what u want flash, example "Nemesis Patch 2.3 SVN090 DM800se Sim2.10 - By vyper and langioletto" and hit flash. Do not tick "Reboot After Flash"! Wait till flash is finish and do not close the page, or hit reboot.
7: Open Sunray Flasher. Tick "With Network" and the "Serial Port" set to COM4 at last fill out the IP settings. And hit the tab "Connect"
8: Now hit from internet explorer flash page "Reboot" and close that.
9: 800se will now reboot the box is recognized and the Sunray Flasher "Flash" tab is dark. Next hit the "Flash" tab and look up "sim2SE_SSL82_110620.nfi". If the flash is gonna successfully u get a notice. After that hit tab "Disconnect" and power off the 800se. Close the Sunray Flasher.
10: Unplug the mini USB and power box up with new image.
Big thanks to Vortex from another forum who wrote the basic.