Upgrading Haiku?

How would I upgrade Haiku to, for example, when Alpha 4 comes out without losing Apps, Files etc.
I did read something about it - can I just pop in the CD and it’ll write over my System folder?

Basically, just pop in the new CD or USB key, and run Installer app.
It let your select the source volume (new alpha4) and the target volume (your current disk).
After a warning that it will copy all the source system’s stuffs over the target ones but will merge all the rest (no Apps, files or settings lost), just click Begin.