For those who don't know... cwm is the advanced recovery console for your device, using which you can :
1. Nandroid backup & restore.
2. Flash custom rom & other advanced updater-scripts.
3. Partition/Format sdcard.
4. Calibrate battery by wiping battery stats.
5. And more...
1. Download this file : http://bit.ly/SoLelm
2. put this in you sdcard (put it directly, not in any folder or anywhere)
3. switch off phone
4. Now Boot you phone in recovery mode by pressing Home Key+Volume Up Key + Power Key together for few seconds until you see samsung galaxy y duos logo
5. After that you will be taken to a menu, in this UI your touchscreen facility will not work, so use volume keys for scrolling up and down, home button to select and power key to go back.
6. In that menu select "Apply update from SD card" and select the zip file which you have recently copied it in your SD card.
7. Done ! Stock Recovery is now change to ClockWorkMod Recovery (the letter color become yellow)