I opened a case with Dell.  They were able to work with me to force downgrade the firmware (includes resetting the unit back to defaults).
Hello all I have a new PSM4110 that came with firmware v7.0.5 on it.  I need to join to a group with a PS5000, PS300's and another PSM4110 with firmware v6.0.7 Firmware downgrades are disallowed in the group by default - I don't need the data on the old unit so it's OK to reset. Is there a procedure for downgrading?  Again, the new unit has no data.  THanks in advance /Philip
EqualLogic PSM4110 Firmware Downgrade from v7