1) You wold need to change the links that point to the old asp pages to point to the new php pages instead.2) the MSSQL Database should you the option to export to a SQL Script, you can use this SQL script to recreate the database in the MySQL server.

I tried exporting using a script about a year ago... It didn't work. There were conflicts in the data so some of it wouldn't import.
I've looked at NavCat which is a tool that works pretty good for transferring data but I lost my motivation to continue as I moved into more pressing projects.


