Ok, sounds like you have the stock recovery...
Now, Assuming that you are rooted...
What you need is the Modded Recovery that Hroark created. ( ClockWorkMod / CWM)
First download this:
Samsung drivers for windows ( install First)
http://api.viglink.com/api/click?format=go&drKey=1153&loc=http%3A%2F%2Fandroidforums.com%2Ftransform-ultra-all-things-root%2F430140-acs-root-transform-ultra.html%23post3332148&v=1&libid=1321059183200&out=http%3A%2F%2Fdl.dropbox.com%2Fu%2F12826399%2FSAMSUNG_USB_Driver_for_Mobile_Phones_x86.exe&ref=http%3A%2F%2Fandroidforums.com%2Ftransform-ultra-all-things-root%2F&title=%5BACS%5DRoot%20for%20Transform%20Ultra%20-%20Android%20Forums&txt=Drivers%20for%20Windows!&jsonp=vglnk_jsonp_132105912189913
then this:
MEGAUPLOAD - The leading online storage and file delivery service
Odin CWM Recovery files posted by Hoark13
Then follow this:
Install CWM with Odin
1. Download and unzip HROARK_CWMv5026_SPH-M820.zip
2. Copy stick.zip to SD Card
3. Install the Samsung USB drivers (if you don't already have them)
4. From a powered off phone put phone into Download Mode by holding Volume Down, Camera Button, and Power button until the Yellow Downloading message appears
5. Plug phone into USB port
6. Open Odin, you should see a yellow box with a com number
7. Select HROARK_SPHM820.ops in the OPS box
8. Put a check in One Package
9. Select the HROARK_CWMv5_SPH-M820_Odin_1P.tar file in the One Package box
10. Click Start
11. When Odin says reset and the phone reboots Hold Vol UP, and Power button until you are in CWM DO THIS QUICKLY BEFORE PHONE BOOTS, IF PHONE BOOTS UP ALL THE WAY START BACK AT STEP 4. you do not have to wait for Odin to say pass, that does not work
12. In CWM go into install zip from sdcard
13. select choose zip from sdcard
14. select stick.zip
15. select Yes - Install stick.zip
16. After it is done installing Press back button
17. Select Reboot System Now
It all came from this thread if you wanna read..
http://androidforums.com/galaxy-pre...od-v5-0-2-6-file-system-recovery-utility.html
When it is installed, you will know its CWM and the latest version all the text will have a blue theme and you will see version 5.0.2.6. If you have that, your golden..
Now you would be ready to install
Hoark's CM7 Beta2.zip
HotfixB Beta2.zip and
gapps using the "install zip from sdcard" option in CWM recovery. (REBOOTING completely each time after one is installed)