ROM Hack Super mario 3d land rom hack help

[BasHeemskerkDEV]

so, i really want to make a simple romhack for SM3DL on my 3ds. i used the rom extraction method by Asia81 with the HackingToolKit3DS file. i first tryed extracting a CIA file and putting my costum music in there, but after i rebuild to CIA, my 3DS tells me there is a invalid NCCH. so i tryed extracting a 3DS file and after i rebuild, i try converting .3ds > .cia. but it immediatly tells me that .cia conversion failed. i went on the internet and searched for a new .cia file, i was convinced that the .cia and .3ds i used earlier were corrupt and i found one that i could install on my 3ds without the NCCH fail. but when i try extracting this CIA i dont get the romfs folder i need to change stuff. can anyone please explain. sorry i cant provid pictures


im sorry if i cant put images (im a new MEM)

i did notice though that in the first .cia i used said a completely different title ID:
different one: 0004000000054000
normal one: 00040000000053f00
i dont know if this has something to do with the USA or EU restrictions

i have tryed decrypting both in decrypt9 and godmode9 but nothing seems to work.

help would be very appreciated!

thanks in advance

 

[BasHeemskerkDEV]

o seems like there were pictures attached.

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ill provide a quick picture of the NCCH fail

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ill provide a quick picture of the NCCH fail

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ill provide a quick picture of the NCCH fail

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ill provide a quick picture of the NCCH fail

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ill provide a quick picture of the NCCH fail

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o im sorry