just search garmin 430 database update and you will find a lot of information. Detailed info and videos on how to do it.
 
If its a waas unit american gps in palm beach area will do it. They cannot do the non waas. Search ebay for more options.
 
this regards the 430-w only?
Not sure. I'll see if I can dig up the interview with the Garmin guy.

Last I checked, the database updates were still available for the 430 using the same basic process (though not the same cards...) as for the 430W. But I haven't looked at that in a while.