How do i flash my DM500+ to Commando 15.1a?

Hello guys, i've been trying to flash my Dreambox DM500+ but with no success...
I have downloaded Dreamup versions "DreamUP_1_3_3_11", "DreamUP_patched_by_forhike_and_natas" and "DreamUP_1_3_3_9"
But they all give me that i can only use the extension file .nfi and not .img...
How can i flash it to Command if it only accept .nfi and not .img?

Quote from master G

Flash the image in telnet using dreambox control center. This was already explained in your previous thread Can i install OpenPLi on Dm500-s??..

Don`t ask us to help you configure oscam, CCcam etc as we havn`t forgot you are using a pay server Got my Dreambox box with gemini and MgCamd, now what?

Nah screw CCcam... I've been reading about it and it sounded too good to be true. After i knew it had a flaw (not legal) i decided to not use it anymore as i intended to do...
Master G, i've been trying to use telnet but i get this all the time:
"-sh: eraseall: not found" :(

Look at this thread i wrote: http://linuxsat-support.com/showthread.php?t=92820

Quote from annie12

Can you ftp to the DM ?

Yes by using Dreambox control center.. or any other FTP software :)

Quote from master G

Which image is on the dm500 at the moment ?

Well i had Gemini 4.7.0, but i have now flashed it to OpenPLi http://openpli.org/download/dreambox/dm500plus/

The only reason i want to change the image is because OpenPLi made it alot slower and it always crash randomly whenever i look at a channel or even zap to a new channel :/

EDIT: This is what i always get:

Quote from master G

If you have an openpli image on the DM500 rename the commando image to root.cramfs
FTP this to /var/tmp folder.. In the openpli menu go to settings then expert settings then update and manual update and it will install..

Howto install the latest software image on your DM500

Thank you, i will try that. I let you know how it went :)

Wait how should the file be named? root.cramfs or root.cramfs.img ??

EDIT 1: Where can i find expert settings? All i can find is System settings and if i click on "Software update" this pops up:
"Are you sure you want to put your box in **STOP** mode?
When the box is in **STOP** mode you need to connect to it with a webbrowser and flash the new image.
Make sure you make a backup of your settings before continuing."