Installation of SAP Kernel 722 EXT on 721

Hi all,

I have systems that were upgraded to SAP Kernel 721 last year and we are looking to upgrade to 722 EXT soon after its release last week.

I understand that from 721 to 722, it's a simple 2 step process of backing up the old kernel directory and installing the new kernel directory over. Does this apply for 722 EXT kernel too?

One question arising is, do I just do a simple backup of the old 721 kernel and switch to 722 EXT by simply overwriting the directory (my OS is UNIX). Or do I have to delete all existing contents in the kernel directory and put the new 722 EXT kernel in?

Cheers,
KT