We already have a guide to root the Galaxy Precedent, a variant of the Prevail, and if you own that device, be sure to check it out. Now, for the rooting procedure on the Galaxy Prevail running Android 2.3.6, read on!
1. This procedure roots your device by flashing a prerooted ROM, which means you will most definitely lose all your data; so back up what’s important before you proceed.
2. Make sure you have the necessary drivers installed before you proceed; if you aren’t sure, download the package in the next section and run SAMSUNG_USB_Driver_for_Mobile_Phones_x86.exe from it before you proceed.
1. Put your device into Download mode. To do this, with your device powered down, press and hold the Camera, Volume Down and Power buttons until you “Downloading” on your device’s display.
2. Connect your device to your Windows PC.
3. Extract the FF19_ROOTED.zip you downloaded above to a folder on your desktop.
4. From the extracted folder, double-click on odin Multi_Downloader_v4.43.exe to run it.
5. Load files from the extracted folder on to Odin by clicking on the relevant buttons as you see in the screenshot below.
Your device should be rooted and have ClockworkMod Recovery installed after it reboots!!
All thanks go to Caeadas for his excellent and detailed post (including the picture you see above) and hroark13 for providing the rooted image. They deserve at the very least to be thanked, so head over to their respective threads by clicking on their names to do so.