I'm afraid kernel 2.6.28 is not available in the repositories yet.
Anyway, to install a pisi package, you just have to double-click on it. This launches the package manager.
Such is life...
I don't suppose anyone knows when 2.6.28 is like to hit the repos?
I can live without an internet & LAN connection for only a little while
Perhaps I should just by a ethernet board...