I am fairly new to rooting / putting custom ROMs on devices; I finally have my phone in a state that I like, after putting Cyanogenmod 7 on my HTC Desire Z. Since I've done this, there have been a few point releases, and a minor release is not far away. However, I don't really know how to upgrade from one version to another (and I couldn't find any instructions on how to do so).
How do I upgrade from one version of Cyanogenmod to another? Is it the same process as installing it in the first place? Will I have to wipe all the data on my phone, as I did the first time?