HP Array Controller HSG V8.7 Software - Manual (Page 227)

Replacement Procedures 5–31
13. In a dual-redundant controller configuration and if the ECB was
replaced for both cache modules, connect the PC or terminal to the other
controller’s maintenance port. The controller to which you’re now
connected is “this controller.”
14. Repeat steps 9 through 12.
15. Remove the old ECB SBB.