Windows server 2003 Domain Controller

I have one small office network without internet connection. I have one PDC and one ADC. Operating system is Windows Server 2003. Now my PDC has to be formatted due to some OS problem. Now my questions are

1)Whether I can make my additional domain controler as a primary domain controller?

2)what will be the proceedure to remove PDC from the system and how it can be taken into line again?

Regards,

Pradhan