I used this guide to sofmod my 4.3U console and it was very easy and selfinstructive, what I would change is in chapter 1 part 3 (Part 3- Make A NAND Backup (NOT Optional, do this,) and
Load HBC, press -HOME-, launch Bootmii
Make a nand backup
Press Power, Power, Power, Reset, Reset (or use gc-controller)
I would write that you need to press this keys on the console and not a remote! That's the only comment I have on this guide, everything else went smoothless.