Changing contribution plugin size

hello i wanted to know if there is a way to change the plugin initial size. because people are trying to upload videos above 20-30mb and it doesn't expect but only expects videos less than 1mb. can someone help me change this.

thank you

Limitations on file size for uploads are set by your server administrator, so you will have to contact them about increasing the POST limit. This is not a setting your can change within the Contribution plugin.

thank you sheilaBrennan :)