How to change (NT)Domain Name after installed ERP?

Hello,

We are planning to change (NT) Domain Name on environment of already installed ERP/BW(WAS 6.40)/SRM/SolMan(NW 7.0).

We know SAP recommend that customer should be Re-install or System-copy SAP-System if the Domain name is changed after installed systems.

However, we do not have enough time and budget for doing that.

Questions:

1). If the (NT) Domain name will be changed, we only need to change the

OS users of service for SAP-System?

(I think that it is needed to change only OS-users of SAP-service. Is there other setting for that?)

2). The method of only changing users of SAP-service is not supported in this case?

(The customer will be not taken the SAP-Official support after doing that?)