How to Change php.ini of Dreamhost Web Hosting?

We usually edit .htaccess to achieve our special demands when we use the web hosting from dreamhost.com. But sometimes we have to modify php.ini to get better results, for example, we often meet the following error when we import posts to wordpress, especially we import more than 7MB files.

We usually have 3 methods to resolve such issures:
1, modify .htaccess;
2, modify wp-config.php;
I have tried these 2 methods for my dreamhost web hosting, failed.

The last one is using Custom PHP.INI auto-installer”, download it from sxi.sabrextreme.com/dh-phpini, upzip the file, and upload dh-phpini.php to your domain’s folder and open it in a browser. An editable php.ini will be created in the domain’s cgi-bin folder in a minute.

The author has thougt very carefully, after you run the code, dh-phpini.php will be deleted automatically.

Now you can edit php.ini under cgi-bin folder, for example, you can modify upload_max_filesize = 20M
to upload_max_filesize = 100M.