ACT E2 100 rev 3 mod Tideglo 100

you can only put it on your USB stick, simplest way is you have a multiboot capable image in flash and install it on your USB stick or hard drive.
The procedure has been posted a lot of times here, either install it through telnet or through a plugin.

you need multiboot uboot,not multiboot img.
img in flash you can put everything you want(only flash images) and if you have installed last uboot you can go to multiboot with usb,bootplus or install E2 from sif extreme :thum:

put image file on usb and rename it to "usb_upgrade.img". Press on the receiver while holding the power button until you see USB Upgrade on the front panel display.