Rookie requesting help extracting and reimporting a .bin file for Jack Box party pack 3

[TinkiWinki]

Hey guys, the title basically says it all! In essence I am looking to edit this bin file, you can actually extract it with 7zip/winrar to view the files but the majority of my troubles come when trying to reimport, I am a begginer and I don't really know what to do and I've invested many many hours over the last week trying to figure it out and I'm just kind of lost, maybe someone more experienced could give some guidance.

here is the bin file.

The past posts I've read about this make it seem like the Jackbox team makes it semi-easy to reimport (the bin file is nearly the same as a regular .zip), but the only script I found for bms was for the first Party pack and I haven't got it to work for the third, so if some one could help me figure out how to make a script similar to this (but for the 3rd party pack), I would very much appreciate it.

I know I'm asking a lot, but I've been blown away by the community here and if any experts could help and maybe even give me a step by step guide on how they did it, I would be extremely appreciative!

[aluigi]

Your link on mega is invalid or it requires a password

[BoggY]

If you can open it with 7z can't you open the archive, and put the files in it without extracting/reimporting ?

[TinkiWinki]

Your link on mega is invalid or it requires a password

Sorry about that, fixed.

[TinkiWinki]

If you can open it with 7z can't you open the archive, and put the files in it without extracting/reimporting ?

I gave that a shot and whenever I messed around with the files, 7zip threw me a "not implemented" pop-up and then with a "cannot update file" pop-up.

[aluigi]

It's a modified zip archive, the first 4 bytes have been overwritten with "JBGP" so the easiest solution is opening the file with a hex editor and overwriting the first 4 bytes with the following (hex):
50 4b 03 04

Now you can do everything you want.

Remember that if you want to rebuild the archive then you must replace the first 4 bytes with: 4a 42 47 50

[TinkiWinki]

It's a modified zip archive, the first 4 bytes have been overwritten with "JBGP" so the easiest solution is opening the file with a hex editor and overwriting the first 4 bytes with the following (hex):
50 4b 03 04

Now you can do everything you want.

Remember that if you want to rebuild the archive then you must replace the first 4 bytes with: 4a 42 47 50

Awesome, works for me!

if you don't mind me asking how you figured it out, did you know it was a modified zip file (or something similar to it) because it could be extracted like one and then slap on the zip hex file signature?

[aluigi]

Mainly by experience, the initial bytes (I mean the zip directory header) had something familiar, it's not rare to find ZIP archives in games with edited magic values ("PK" and the header identifier like 0x03 0x04) and my zip.bms does the job automatically, but in this case it didn't work because all the rest of the ZIP was intact, just the first 4 bytes were overwritten.
The reason why you were able to see the files with an archive program is that the ZIP format has the main information located at the end of the archive and they were correct but the program didn't recognize the first 4 bytes when tried to extract the first file.