To raise the PHP Upload Limit for your website simply do the following:

Create a blank text file called php.ini (if one doesn't already exist).

Put the following line in it:
upload_max_filesize = 10M

(replace 10M for whatever size in Megabytes that you would like the max upload set to)

Then place the file in your public_html folder or deeper in your dir structure (preferably only where you need it) and that's it.