Not sure why you would goto ErmaC v1.4 when Rogero 4.30 v2.0 is out?
Anyways how I got to Ermac v1.4 was:
Upgrade to Kmeaw 3.55, QA toggle and make sure it worked, boot into recovery and upgrade to Ermac v1.4 - that simple.
Also yes, the PUP must be on the root of your flashdrive which needs to be FAT32.
Also it will not destroy your saved games or any backups you currently have on your PS3 etc. You may need to have your eboot fixes resigned in order for it to work under 4.30 if they were patched to work on 3.55
If you want to know, I downgraded using Rogero's downgrade guide and then upgraded to Rogero CFW 4.30 v2.0 - it worked fine