Maises has released a computer app named LordSELF, that will let the user edit PS3 SELF/SPRX Files, here is a quote from the readme:
What is LordSELF?
It is a try to clone the famouse LordPE PE Editor
for Playstation 3 SELF/SPRX Files.
how to use:
1) Explorer Shell Extension
run LordSELF -> Options “Register Shell Extension”
so you can directly load via right click in Windows Explorer
(requires admin rights once to set registry entries)
2) drag & drop self/sprx into exe
3) commandline “LordSELF file.self”