I know you've already tried the wizard inbuilt into RU2 as per your other thread and Biran's suggestions, so you may want to try the sylinkdrop tool instead:
http://www.symantec.com/docs/HOWTO81179 #EDIT# Whoops wrong link #EDIT#
I've always preferred this option as I've generally found it more reliable. To run it on a remote machine however, I normally end up scripting it and pushing that script out either using GPOs or Altiris. A common script I use is something like:
If not exist %temp%\newsylinkfile.xml (
Xcopy \\<NetworkLocation>\newsylinkfile.xml %temp%
“%programfiles%\Symantec\Symantec Endpoint Protection\<ClientVersionNumber>\Bin\ SylinkDrop.exe” –silent %temp%\newsylinkfile.xml)
The newsylinkfile.xml should be replaced with the name of the file exported from the new SEPM environment.
The <NetworkLocation> is a share (accessible to SEP clients) hosting the newsylinkfile.xml file. Read permissions are required to this share and file.
The <ClientVersionNumer> is assumed to be “12.1.2015.2015”, in your case.
The script will require changes if running against a 64-bit machine, replacing %programfiles% with %programfiles(x86)%”. The differentiation between processor architecture can be included in the script with additional “If” statements, or accommodated via WMI (for GPO distribution)
#EDIT2#
You could also do this with psexec if it's a one-off, but I've not tried it myself