Hi
do you have to keep the 6509 online for this or do you have a maintenance window , I know you can sync between certain sups once the flash and ram match even if there different types not sure about these 2 though but if I was doing it I would get a window , shutdown the 6500 pull the flash card from the sup32 then put the new image on the flash card bring up the 6500 on the new sup2T , then pop in the other sup and sync between them and get the redundancy setup
One thing to note on a 6509E the sup2T must be used in slots 5 and 6 only
•Supervisor Engine 32, Supervisor Engine 32 PISA, Supervisor Engine 720, Supervisor Engine 720-10GE, and Supervisor Engine 2T must be installed in slot 5 or slot 6.
you would want to configure SSO stateful switchover between the sups too
http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst6500/ios/12-2SY/configuration/guide/sy_swcg/stateful_switchover.html#17781
redundancy
main-cpu
auto-sync running-config
auto-sync bootvar
mode sso