Elf files?

ok so i just got usb firm loader to work and im now looking for things to edit i have ran across a few files that when edited make me think they may be elf files with just a different name for example they have this

Code:

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SCE............@.......€......Dè...............p...............Ð...............€.......à.......ð.......p.........p..@..............@.............ELF...f........

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(note the ELF bit mentioned at the end of this quoted code) with a load more codes after that but im thinking this .sprx might actually be a .elf

so in short how do i edit ELF files as i will need to know this to try a few more things, i have google'd around a bit but cant find anything decent

any help would be great, thanks