[cisco-voip] IPCC Express Premium 4.0(3) upgrade to 4.0(5) ?

[Dane]

Can anyone share with me some info and experiences on upgrading IPCC
4.0(3) to 4.0(5)?

Is it an upgrade, or a backup then install and restore process?
Painful or painless?  :-)

I have two boxes, primary and secondary HA.  Have never done an IPCC
upgrade so not sure about it all.

The IPCC implementation is very basic so not too worried if I had any
major problems and having to redo it all as a worst case scenerio but
hopefully it will not come to that.

Just looking for any real world experience and advice from others who
have done this before I get started.

Thanks,
dane