Trying to raise the upload limit

The past few days I’ve been trying to increase the upload limit of my site. I want people to be able to upload their own video clips using a script but since the default on DreamHost is 7MB I was hoping to raise it to 30MB.

Anyway I’ve been searching through here and Wiki and I thought I had it figured out, and followed it using SSH but still my site timesout when I try to upload a file larger than 7MB.

I don’t want to upload my own php so I tried this way instead.

Can someone please post an easier step by step guide? I thought I was starting to understand SSH (I use Putty) but obviously not.