I really fail to see what all the fuss is about. If you have a working Intel Mac, and a bootable system disk of a Mac operating system 10.*, then you can instal it on that Mac regardless of what operating system was already there.
Just stick it in and it will lead you onwards. If that means erase disk and instal, ok. You'll still have a fully functioning Mac afterwards, with the new OS on it.
Of course, anyone sensible would have copied all their data files to a removable/another hard disk media before starting this operation.
