How can I upgrade my LG Optimus P350 from Android 2.2.2 to 2.3 (Gingerbread)?
Here is a tutorial to update your phone to 2.3: http://www.ninjaromeo.com/upgrade-lg-p350-optimus-me-gingerbread/. The LG Support Tool would be the best method to find and update your phone to the latest official version. Follow the instructions on backing up your phone as there isn't a guarantee that your files would remain untouched, especially text messages.
You must assume that LG doesn't provides updates for any of its phones.So,you'll have to install a custom ROM for your phone.
Follow the instructions mentioned in the below link -
How to Update LG Optimus Me P350 with Android 4.1.2 Jelly Bean CM10