SpeedFreak
PRS+ installer's advanced menu allows you to flash Fsk and root partitions. (there normally no need to change boot/root2, not to mention, messing with those 2 partitions could brick your reader forever)
Replace 1.1.00.18040.root and Fsk.img files in PRSPInstaller\Sony Reader\software\firmware\505 folder. Generate md5 hash of those files (using this
http://www.pc-tools.net/win32/md5sums/ or any other utility) and put it into corresponding .md5 files.
Then in expert menuÖ
Force flash Rootfs => will flash root partition
Force flash PRS+ Firmware => will flash Fsk partition