why can't i unpack elf file ?

hello again :)

i have an elf file and i want to add new splash screen and menu screen to my hdloader but when i unpacked the file none of the program able to change those screens for example hdl edit or BMP BATCHV4[1].00 or HDL_AIO_2.2 after unpacking when i want to apply some changes says that the file might be badly unpacked or something ....... why is this happening can anyone tell me what i'm doing wrong ....?

so the real question is : how to change those images (splash creen and menu screen) in hdloader .... is it possible that the elf file won't be able to unpacked or edit ...?

thanks