VCenter 4.1 - upgrade database from 32-bit to 64-bit

Hello:

Running vCenter 4.1u1 (vCenter build 345043) on 64-bit, with the database housed locally on a SQL ExPress 2008 R2 instance.  The original install was to a SQL Express 2005 instance, but the SQL instance was upgraded to allow for the larger databse size (10GB with 2008 R2 vs 4G with 2005).  Upgrade was done with the 32-bit version of the SQL Express 2008 R2.

Now looking at upgrading to vSphere 5.  I'm already on a 64-bit OS - does the SQL EXpress instance also need to be 64-bit?  If so, how do I move from the 2008 R2 32-bit version to the 2008 R2 64-bit version?

Thanks