How to root Galaxy ACE on Gingerbread 2.3.5 & 2.3.6

Rooting
Copy the above files in your SD card files are named upd_1.zip (for rooting) and unroot.zip (for unrooting).
Switch off phone and restart in Android System Recovery mode i.e press and hold Menu+Power keys till it reboots in recovery.
Go to "apply update from sd card" and select upd_1.zip. The process will be completed soon.
Restart your system. You have successfully rooted your phone. In my case I got a Force close of application once but do not worry about it.


Unrooting


Switch off phone and restart in Android System Recovery mode i.e press and hold Menu+Power keys till it reboots in recovery.
Go to "apply update from sd card" and select unroot.zip. The process will be completed soon.
Restart your system. You have successfully unrooted your phone.

Tutorial Video: