you can probably do this by pulling the setup audit trail information which gives you the list of all changes done in a csv file that you can apply filters to get the changes done by one particular user.
For more information refer to the following article http://help.salesforce.com/HTViewHelpDoc?id=admin_monitorsetup.htm&language=en_US
For more information refer to the following article
http://help.salesforce.com/HTViewHelpDoc?id=admin_monitorsetup.htm&language=en_US