Carrisonfire

I'm looking to rip assets out of Subnautica and put them into Below Zero. Before anyone points out the devs have asked people not to do this, I know. I don't plan on uploading these mods anywhere, I just want them for my own use. Is there any free software that allows this? I'm familiar with programming (C++ and Java but willing to learn whatever) but have never created a mod before beyond modifying values in some files.