HELP! Need a “way-back” machine to uninstall NEW Documents To Go & revert back to OLD

How do I revert my iBook back to the older version of Documents To Go that I was using as of this morning? I’ve tried trashing the new version, & re-installing the old version, but each time I do, it says a newer version already exists on my computer. The new version is a 30-day trial, so my original version should be in my computer somewhere, right?

I need to get the older version back because the new version needs Palm OS 5.0 or higher, but my Palm is old (m130) & can’t run the 5.0. If I don’t get this fixed, I can’t access any of my documents on my Palm. Can I turn back time somehow to make it like this never happened at all? Any answers?
😕