Its honestly not that bad bud. just follow one of th detailed tutes for the iphone.. using iphoid.. that way you skip using vmware and ubuntu on the computer.
Its quite fast to get openiboot on the iphone.. once thats done, its a simple process of putting the neccisary files onto the iphone using filezilla or winscp and changing permissions to 777 ( Sorry if some of this doesnt make sense, the tutorials explain indepth).
+there are multiple downgrade threads popping up every hour or so, just pick and read and see if it makes sense.