FSMO Role back to DC. what to do with ADC ?

Dear All,

recently my Primary Domain Controller got Crashed i had transferred all FSMO Roles to the ADC successfully. and reinstalled my Primary domain controller windows again. now i have a question i want to transfer FSMO roles back to the newly installed Domain Controller and want to make it PDC. after transferring FSMO roles from ADC to DC is it compulsory to remove ADC ? or what ADC will act like ADC ? or i have to remove it from Domain / network ?

Thanks 

Muhammad Zaman