GT-P7510 Android version 3.1 I'm in New York and I bought it from Best buy.
Sorry for the late reply.
Two ways to update.
Go to sammobile.com. There you'll find the Samsung files.
Download the one for your model, and flash it with Odin.
It's recommended you do a factory reset first. After the reset, just set up your tab to get it going. Don't update any pre-installed apps or re-install any of your apps.
Then flash the new file from sammobile. Then you can proceed as if you just bought your tab.
The second way is to use Kies. If you use Kies, you'll have to do a factory reset first to get Kies to connect with your tab (a bug somewhere prevents Kies from connecting to the tab if the tab has been updated; factory reset solves that problem).
So, using Kies, factory reset first (don't update anything, just get it going).
Fire up Kies, connect tab to PC. Kies should see the tab and tell you an update is available.
Update, and then you can set up your tab. Update apps, re-install your apps, etc.
Flashing with Odin:
Factory reset first, don't update anything, just enough to get it going.
Put your tab into download mode, launch Odin on your PC, connect tab to PC.
Flash the new firmware file you downloaded from sammobile.
You can then continue to set up your tab, which will now be running ICS.
I've done it both ways, and don't really have a preference. Flashing with Odin may be a bit faster. If you're new to all of this, I'd recommend using Kies.
Whichever way you do it, a factory reset isn't absolutely necessary, but it's highly recommended. It gives you a nice, clean installation of the new OS.
Make sure you back up anything on your tab you want to keep, like photos, e-mails, etc., as a reset will delete everything. It's like re-formatting you computer.
Also, if you use the Odin method, you'll need to download the USB drivers from Samsung and install them on your computer first. If you use Kies, Kies will install the drivers.