If you've been using a married name and want to revert to your maiden name on your passport, you need to apply for a new passport. You cannot apply online.
You need to submit:
Otherwise, you will need to submit two official documents that show you've been using your maiden name for two years.
Our How to Apply for a Passport Guide takes you through each step of your Irish Passport application
You will need your 11 digit application number - this is found on your receipt.