Change Desktop Enviroment from Plasma to i3

i wannna change my DE from plasma to i3, and based on my research, fresh install is the best way. So, is there a way to fresh install without losing all my current data(up to data package, software config, etc)? because download speed are painful as hell in my area

Or should i only replace my DE from Plasma to i3?

You don’t need a new install. You install i3 and choose in the login manager that you want to use i3 instead of KDE.

This way, you can easily switch between them, if you need to. When you’re happy with i3, you remove the KDE packages and you’re done.

do i need to reconfigure my software (like OBS, Steam Library)? because its honestly painful for me to reconfigure

No, that’s the beauty of not reinstalling the whole system. Your home directory stays the same.

Fresh install is the best way because Manjaro i3 edition provide a custom configuration but you can build your own with basic i3. You can also take the different files provided in Manjaro i3 edition if you want and if you know how to do that.