Q: HI I have ios 3.0.3 need to upgrade into 5.2 for support more games how can I ...

I suspect you have the 1G (original) iPod touch . Those canonly go as high as 3.1.3. If you iPod does not have volume buttons on the upper left edge and no internal speaker it ia a 1G

Otherwise:

To update

The Settings>General>Software Update comes with iOS 5 and later.

Connect the iPod to your computer and update via iTunes as far as your iPod model allows

iOS: How to update your iPhone, iPad, or iPod touch

A 1G iPod can go to iOS 2.2 via iTunes and iOS 3.1.3 via

Purchasing iOS 3.1 Software Update for iPod touch (1st generation)       

https://buy.itunes.apple.com/WebObjects/MZFinance.woa/wa/touchLegacyLandingPage

- A 2G to 4.2.1. Requires iTunes version 10 or higher. If a Mac it requires OSX 10.5.8 or later.

- A 3G to 5.1.1  Requires iTunes version 10.5 or later

Identifying iPod models