Identify SLA changes required for FA accounting

Client is currently in EBS R12.2.5 and has been using Oracle Fixed Assets for a long time. They have a 6 segment Chart of accounts i.e., Segment1 Company, Segment2 Account, Segment3 Dept. Segment4 Division, Segment5 Asset Number etc. For Fixed Assets accounting under Cost, Depreciation Reserve and Depreciation only Company & Account segments are currently used. As part of new acquisition & process improvement Client wants to utilize the Segment5 (Asset Number) going forward by adding asset number values to this segment5.

The requirement is FA Cost, Depreciation Reserve and Depreciation entries shall have segment5 values populated when we generate accounting in FA. The assets are mainly capitalized from Capital Projects and the depreciation charge account is assigned by Projects team. The segment5 value assigned for Depreciation charge account should be used in the Cost & Depreciation Reserve as well. Can someone please explain the changes to be made for Fixed Assets SLA setups? Is it possible to move the cost & depreciation reserve for existing assets for default segment5 value to the correct segment5 asset number? Appreciate your inputs.