Advice on adding new PS 6100 xv please

Hello

My customer currently has a ps 4100 with firmware 4.3.6 owning windows luns and hyper v 2008 CSVs. This is now very full with only a 100 GB free. They also have a PS6100xv with firmware 6.0.1 again with windows exchange luns. This unit is also very full. Both units exist in their own groups unfortunately. We would like to purchase a new PS6100xv and migrate all data safely whilst creating a single storage group.

Any advice much appreciated.

Mdw