Exchange 2007 Edge Transport role

Hi, We are in the process of building 2 x Exchange 2010 HT & CAS and 2 x Exchange 2010 Mailbox Servers in preparation for Office 365 migration. We also have 2 x  Exchange 2007 SP2 Edge Servers in DMZ.

My question is when we have built the new Exchange 2010 servers, do I need to rerun the edge subscriptions? What is the actual process? If it all I need to rerun the edge subscriptions process do I need to run it from both the edge servers and import the xml file twice from a exchange 2010 HT servers?

thanks

Merwin

Merwin