Compiling PHP for MS SQL Support

I am new to Linux and have NEVER compiled PHP. I have PHP 5 and need to compile it with MS SQL support. Per PHP docs, I installed FreeTDS and tested it and it works. Now I need to (re)compile PHP to get the support I need to access MS SQL databases. I am on a Ubuntu 6.06 version of Linux. Again, PLEASE keep in mind that I am new to all of this. I tread VERY softly doing this! (I am on a VMWare virtual server and have made a clone drive as a backup.) Am I correct that my first step is to see what is already compiled into my version of PHP using php -m? I have that list. I assume that my next step is to get the PHP source for PHP 5.1.4. From here on I do not understand clearly by reading the docs I have searched for on the Internet through Google. Is there a place that has a VERY clear, step by step process to compile PHP? Any and all help is GREATLY appreciated. TIA. Mike