Hello,
In case of SEP 12.1.RU2, you no longer need Sylink Replacer. That functionality is built in to the SEPM now. See the attached screenshot, or the following document:
Restoring client-server communications by using a client installation package
http://www.symantec.com/business/support/index?page=content&id=HOWTO81455
(The title is a bit misleading and should really be "Restoring client-server communications by using the Communication Update Package".)
The clients can be either 11.x or 12.1 (previous version than 12.1.2).
In case you are using any lower version to SEP 12.1 RU2, then you would have to contact Symantec Technical Support and create a case with them.
How to create a new case in MySupport
http://www.symantec.com/business/support/index?page=content&id=TECH58873
Phone numbers to contact Tech Support:-
Regional Support Telephone Numbers:
- United States: https://support.broadcom.com (407-357-7600 from outside the United States)
- Australia: 1300 365510 (+61 2 8220 7111 from outside Australia)
- United Kingdom: +44 (0) 870 606 6000
Additional contact numbers: http://www.symantec.com/business/support/contact_techsupp_static.jsp
Hope that helps!!