I did this today, replaced a 412 at R4.1 to a IP500v2 R9.
These steps I have done:
I first recreated the SD card to R9, then I copied the R6.0 ip500v2.bin file in the SYSTEM folder of the SD Card.
Put the SD card in the chassis without any base cards and power up.
Send the 4.1 config offline to the IPO, it will ask you to upgrade from 412 ( or 406v2 ) to IP500, confirm and reboot IP500.
When running insert the new licenses and take a copy of the config ( just to be sure if afailure occur later on )
Turn off IP500v2 and copy the R8 ip500v2.bin file to the SYSTEM folder of the SD card.
Put the SD card in the chassis without any base cards and power up.
When running take a copy of the config.
Turn off IP500v2 and copy the R9 ip500v2.bin file to the SYSTEM folder of the SD card.
Put the SD card in the chassis without any base cards and power up.
When running take a copy of the config.
Power down, insert the base cards and power up again.
Check the config and adjust what needs to be changed, note that the trunks are OK, sometimes tha old trunks are not assigned to the added hardware so delete the old trunks and re-program the new ones.
In my case the old tri=unks were added correctly to the new hardware ( Dual PRI and a BRI8 ).
Make sure to correct all errors shown in Manager.
Done.
in my experience any other route leads to strange behaviour like CLI presentation on analog station fail intermittend, analog stations do not ring randomly, digital sets with wrongly formatted display or no display at all etc.etc.
I never do the R7 step because all docs say to upgrae to R8.0 and then to R9.
The R6 step is just to make sure that the alog stations work fine after the upgrade.
The whole process takes about 90 minutes but the advantage is that it is done well, if no other changes are necessery you can replace the old system with the new oe and leave the premise knowing you won't have to go back for strange problems.
Wow, typing this took nearly as long as the upgrade process...