Industry Codes

Hi, I know this questions has probably been answered a million times, but I can't seem to find sufficient explanation on the message board. I am trying to bridge 1996 industry classifications to the 2006 classifications. I have read on the message boards that there are several versions of these classifications (SIC - 528 - 509, etc), but I have not been able to figure out which of those 1996 and 2006 fall into. Nor have I been able to find any instructions on how to apply the classification bridges I've found on the downloads page (library20.ima, the 528 to 509 scheme, etc.). I believe I need to install the library20.ima file somewhere, but there is no clear instruction on where that would be. I'd rather not go poking around in the program files without knowing at least what to look for. Surely there must be a general document that runs over this information with a general guide on how to operate these changes, but I can't seem to find it. All I've found is the thread nailed to the top of the Data Questions forum, but to be honest, the conversation really doesn't answer the question very well (i.e it lacks a list of years under which each classification system was used, instructions for disaggregation/reaggregation of data from one system to another, any explanation of where any downloaded files should be placed on the IMPLAN appliance, etc.). Thanks for your help with this. I also need to convert the 1999 data, but it appears to be in the same format as the 1996 data so I should be able to repeat the steps once I figure it out. Thanks again.