If you are a user of Samsung Galaxy Ace and want to install ClockworkMod Recovery on this device you are on a right place below you can see step-by-step guide for this purpose, but make sure that you have a Galaxy Ace model number S5830 because below steps are jut compatible with this model. Also make sure that you have manage your back-up because below steps can damage your data.
You also need the battery at least 70% charged so, below you can see the guide for installing ClockworkMod Recovery V5.
Download ClockworkModRecovery 126.96.36.199 from here which is Applicable to Gingerbread
And you need to place it to your sdcard
Now reboot in recovery mode
Select ‘Apply Update from SD card and select the CWM zip file placed in your sdcard.
Now just do the restart.
For verifying, go into recovery again you will find that recovery has been updated to CWM Recovery.