From Brendan at RPI:
Sure probably the same way you installed them originally. Locate the system that is being updated by the MP and then copy all of the EXEs DLLs NONE of the xmls though, And only the directories that do not contain installation specific data. (IE not the POLLING folder structure, you may not want the SECADMIN folder either etc.
That said if this this just an 8 series server you can simply add all 3 BTF subs to the same ECM installation. You just specify a path for each one. You can limit user access via secadmin.
If this is a shared 8/9 server where you a V9 ecm and a V8 ecm though you need more than one instance of ECM and will have to manually update the second installation.