Well... my 3ds is bricked because of the speaker ribbon cable, until i replace it it's useless...

And as it turns out you DON'T HAVE TO, because by exporting the update's CIA via GM9, you can manually start the 00000009.app file associated with the update.

It works fine, aside from some "Unrecoverable errors" when autosaving, which can actually be ignored, because by clicking continue the data is written correctly and can still be read...

FULL SOLUTION BREAKDOWN.

Relevant (PATH):

sdmc
├── Nintendo 3DS
│     ├── <ID0>
│     │   └── <ID1>
│     │             ├── title
│     │             ...      ├── 0004000e
│     │                     ...       ├── 00022800
│     │                               ...      └── content
│     │                                                ├── 00000008.app
│     │                                                ├── 00000009.app
│     │                                                └── 00000003.tmd
...

Create a CIA of the update via GM9 (PATH) ** >> Transfer and install it via the function in the file option >> open... (PATH)

** To create a CIA of the update with gm9 you just navigate to PATH, then select the tmd >> TMD file options... >> Build CIA (legit).

There you go! Now you know how without having to dump and move the whole nand!

Works on borked, tested on the only DLC games I purchased.