You download the Installer as an Archive from the R-Comp website and run it directly from the archive.
It also allows you to read the changes
Clicking on the Upgrade OS will bring up a task window which automatically perform the upgrade, including reflashing the ROM. It warns you very clearly not to interrupt the process or you may not have a bootable machine.
Once done, click on space bar, reboot and welcome to RISC OS 5.28
|f you are an R-Comp customer, this is by far the simplest and safest way to update your machine and probably takes less time than reading this review.