Transfer old process instance approvals from old version of the process to new version activated ver

Dear Team,

Requirement : After GO live , we have got multiple enhancements in a process which is current LIVE in prod. but what happens when we create a new version of a process , old process approval requests still sits old version of process ( during submission they used old version of the process).

But customer wants that new changes should be there in already existing process approvals.

is there any way to map existing process approvals to new version of process ? or is there any way to update the metadata of a process.

Need your support on priority.