Downgrading from 1.12 to 1.11 or lower

[LightOfMetal]

I remember trying modding on a mac a while ago, and had trouble because the MPQTool doesn't have a txt2bin 1.12 converter, and the 1.10 and 1.11 wont work with 1.12. Since I don't think the MPQTool's developer will be updating for 1.12, I figured I'd ask if anyone knows how to downgrade from 1.12 to 1.11 or lower.

There's one more stipulation - reinstalling wont work, because I'm using the downloaded version of Diablo II (from blizzard - the digital download, not illegal or anything), and so reinstalling just makes another copy of 1.12. Anyone know how I could pull this off?