[CentOS] upgrading from CentOS 7 to 8

I searched a bit to see if there is a way to upgrade from CentOS 7 directly to CentOS 8.  I found RHEL instructions but not CentOS.   Although they probably should be/would be similar, the instructions I found enable a rhel repository to get the leap command, which I can't seem to do in CentOS.

Does anyone know if you can do an upgrade yet.  I know they had been working on it in the past.

also - when they say upgrade (for example on the rhel pages), is it in place meaning I can leave my files/data there, or is it strictly a way of installing the OS that is going to wipe out my files?

Thanks in advance. KM