The patch isn't from the same person though.
@Nagato provided us with tools, but my team and I have been the ones working on the patch right now.
Regardless of that though, it
is that simple. If you opt to change the "data_release.l7c" file, you will ONLY be changing that file, not uninstalling/reinstalling the game and losing data. There is no risk in replacing that file. It is worth noting that it isn't as easy as replacing assets and extracting a bunch of files into the game's archive as EVERYTHING for the game is stored in the "data_release.l7c" file. If you opt to do things via the VPK method, you will lose your data, but that is nothing that can't be backed up and restored using tools that are readily available and easy to use (rinCheat, SaveDataManager).