ROM Hack [Help] 3ds devil survivor overclocked Target.bin unpack & repack

[greenbingo]

how can i unpack & repack this Target.bin

this file is 3ds devil survivor overclocked Target.bin,Target.idx,Target.ndx



http://www.mediafire.com/download/sr78u7ux0dkuyof/decrypted_romfs.7z



i think this files

'Target.ndx' with the file names
'Target.idx' with the file pointers
'Target.bin' with the file datas