step 1: stop all gg processes
cd /home/oracle/ggs
ggsci

$stop EXTRACT *
$stop REPLICAT *
$stop MGR

step 2: delete the process groups:

dblogin userid ggs_owner password g
delete
EXTRACT *
delete
REPLICAT *
exit

Step 3:In windows, remove GGMGR service
C:\ggs\install deleteevents deleteservice

Step 4:In Windows,
delete two gg related DLL files
(I didn’t see them in gg11gr2):
del c:\windows\system32\CATEGORY.DLL
del c:\windows\system32\GGSMSG.DLL

step 5: remove the gg home directory:

rm  -rf ggs

step 6: log in as sys and drop the gg owner user:
sqlplus / as sysdba
SQL> drop user ggs_owner cascade;