How to Convert Block system DPE to Unified system DPE

Hi Team,

We have VNX5400 DPE with block system OE ver 05.33.009.5.238. Though we have extra hardware Control station and Data Mover Enclosure, the DPE needs to have a unified system OE for the DPE to integrate with the DME for upgrading the Block functionality to Unified level. 1) Do we have option to upgrade Block OE to unified OE in same vault drives, or 2) Can we install some other vault drives from some other VNX5400, which already have Unified OE, without any risk of crashing. if so, will 2 such vault hard drives suffice, or 4 are required.

Please provide the solution of above issue.