Flash0 questions

So im trying to change fonts / icons and the like, and i want to make a backup of my flash since this is the first time ill be "messing" around with it. I saw a program called x-flash but it seems to only have a 1.50 compatibility. Im workin on a slim 3.90 M33-3. Any advice?

Also, most of the tutorials i am finding for font and icon modification are using 3.03 oe-c. Will running my higher version be a problem?

So you want to back up your flash?

While in the XMB press select and the vsh menu will pop up.
Then go to the 'USB Device' option
switch it to flash0
go into usb mode
copy the files over to your PC.

ok i didnt think it would be that simple. Sounds good.
Ok when in recovery mode, there are USB fash0, 1, 2 and 3. What are the purposes of these?

flash1 is another place with flash files.
3 and 4 are empty.

but only Flah0 has files that i would need to flash. Like cintro and gameboots. Anything special that stands out in Flash1?