Transition from NetBackup TL to EMC DataDomain

Dear Experts,

We are currently having NetBackup 7.5 on a media server, with back up done on Tape Library (TL).  We are planning to remove the TL and put EMC Data Domain, and to make use of DDboost feature. Please let me know the safe and smooth way of transiting from the old to new back up. I would like to backup the data on both TL and DD for sometime before removing the TL. Please let me know the best practices followed.

I came to know that 7.5 has to be upgraded to 7.6 to support DD VTL. Please let me know if there are any other key points to be taken care.

-Regards

SA