An engine update changed my PHP script. How do I fix?

The church I work for uses a WordPress site, which I just started managing, and the Dreamhost engine we use with the site did a spontaneous update and didn’t inform us. Long story short – I was informed by the previous web manager (who is still our site host) that the update deleted the PHP script we used before, which changed the maximum file size upload. Now we can only upload files in WordPress up to 7 MBs. This means we can’t upload our sermon podcasts directly thru WordPress anymore; instead we’d have to use File Transfer Protocol (FTP). I’ve used FTP through my work at a newspaper but I don’t know how to access it for our site. We would really like to get our site back to the upload capabilities it had before or figure out how to use FTP. Help?

My site is coldspringsonline.com.