Hi,
I am highly experienced in PHP and I should be able to do this for you quite quickly.
I wrote three days as the delivery time, however if the code base is relatively simple and everything goes smoothly it could take as little as a few hours. If you accept this bid soon and send the details then I can get started straight away and it could be ready in time for tomorrow morning for you (it is 1:30pm here for me).
I would make a duplicate of the site to run on my testing machine with development PHP settings. I would do all the debugging locally and then upload the completed files in one go, and test them once more on your server. This approach will ensure that the conversion is done neatly and thoughtfully without any disruption to your website.
Please contact me if you would like any more information.
Regards,
Edward