Go to path
/usr/sap/<SID>/<sysno>/SDM/program
Stop SDM service
./StopServer.sh
change the mode to standalone
./sdm.sh jstartup "mode=standalone"
change password of your choice
./sdm.sh changepassword "newpassword=password"
change mode to integrated
./sdm.sh jstartup "mode=integrated"
Now your SDM password is changed and started SDM.
