I would consider this the easiest way:
1) go
here, see SETUP, click on Assets and download v1.0_sdcard.img.7z, extract the image, and use
Win32 Disk Imager to flash it onto a tf card (4GB capacity is enough), should be as easy as plugging the tf card into your computer, running the tool, selecting the image, and then pointing the tool to flash it onto the card.
2) create a linux usb flash disk (I'm using xubuntu), plug it into the computer, restart and boot into the linux operating system, download flasher.tar.gz from the release page
here (again, go SETUP, click on Assets), and extract the Setup folder from the archive to your linux desktop.
3) take the handheld (turned off, no tf card inserted), connect it to the linux pc, press and hold the start button on the console, and turn it on, keep holding the start button for about 1 minute, then release.
4) open the setup folder on your linux desktop, rightmouseclick any empty space, open the console, type
sudo ./flash.sh and press enter. The handheld should get flashed (you may have to confirm the flash start on the handheld screen), once the process is done, the console window on the linux desktop will let you know. Once done, turn the handheld off, disconnect it from the pc, insert the tf card, and turn it on.
I find booting into linux easier than messing around windows drivers. Creating a linux boot flash drive is very easy, just google it.
Also, the performance issues interfere with the key input sometimes, making an experience with any game that requires quick and precise controls less than ideal. So currently, the handheld is pretty much RPG/turn based games only.
And I still didn't find a way of expanding any partition on the flashed tf card, so any space above approximately 2.5GB will be unavailable/wasted.