If you would like to modify existing records to change the format of the full name value after the import/addition of Contact data, you can write a Workflow to accomplish this as follows:
· Navigate to Settings>Processes>New. Give it a name and set it to run on the Contact
· Set it to run on demand.
· Add a step to update the Contact record.
· Click set properties, click in the first name field in the left pane. In the right pane, under look for, choose Contact. In in the lower box choose first name. Click Add, then OK. You should see a yellow highlighted text appear in the first name field on the left pane.
· Click Save and Close.
· Activate your workflow.You can then run this workflow on the records whose Full name value you would like to modify.