Convert .aspx script to .php MySQL

I have a client who is currently hosting their website on a Windows 2000 server and they are ready to move over to a much more stable linux server. However, their current website is running an attorney / law firm script written in .aspx with an MS Access database which I need converted to .php with a MySQL db. All of the script client as well as admin data needs to remain secured as well as their login information needs to remain the same so that they will have no issues logging in once the site is live and running on the linux server. I have seen quite a few software programs that will do this automatically. However, I do not really want to spend the $130 plus dollars on a software program that will most likely only be used one time. Please only accept the project if you know both .aspx .php, MySQL, and MS Access. In addition, only english speaking programmers will be considered. If we cannot understand eachother how can we possibly work together. Sincerely