Problems getting RISC OS 5.22 installed

Hi Everyone.

I have downloaded the Iyonix 5.22 ROM and tried to install it to be told I need to upgrade my version of !Boot. No problems, I downloaded HardDisc4 image V5.22 and tried to install this using the InSituBootUpdate thinking I had HardDisc4 V5.20 installed allready ( same as the ROM ) and was told I needed V5.20 installed before I can install V5.22. Now im a little confused. Not sure how to procede from here as dont want to end up bringing my machine to its knees as i use it everyday. Im sure there is a simple straight forward way to solve this but i dont like messing around with OS issues so dont feel comfortable experimenting.

Any help much appreciated

Greg