Here from the kartu original post (with the addition of the names of files for 650):
Click here for the links:
https://www.mobileread.com/forums/sho...64510&page=107
Originally Posted by kartu
To install PRS+ on x50 models:
1) Install CFW from amutin or boroda (found here)
I installed boroda: PRS650.Flash.Package.1.05k.zip
(you should simply execute flash_reader.bat with the Sony reader to the
usb and wait a double reboot of the reader)
2) Unpack corresponding launcher file into the root of internal memory. You should get test-startup folder if using launcher for boroda (porkupan) or simply test.sh if amutin.
I unpack this file in the root: PRSP_x50_Launcher_boroda.zip
3) Unpack PRS+ installer into the root of internal memory. You should get PRSPInstaller folder with subfolder prsp and some files.
I unpacked PRSP_650_2.0.9alpha_Installer.zip
4) Restart the reader
5) Delete PRS+ Installer. (but not the launcher)
To uninstall PRS+ from x50 models:
1) Unpack PRS+ installer as in step 3 above.
2) Delete prsp subfolder in PRSPInstaller folder
3) Reboot
4) Delete PRSPInstaller folder