Sure you can use, because there is CyanogenMod 9 based on Android 4.0, for your Samsung Galaxy Gio phone. And you can follow the instructions from this post.
However, no one shall be held responsible for any data lose or damage caused after following the instructions, if you follow the procedure correctly you will be fine. So follow it at your own risk.
Make sure you read these requirements first:
- This only for Samsung Gio S5660.
- Have at least 70% battery power, for this rooting process.
- Backup you important data beforehand like Contacts, SMS, Music and Video, SMS.
- Enable your phone USB debugging. Do so by going to Settings > Applications > Development > USB debugging.
- Disable firewall and all antivirus, also close Samsung KIES if it's on.
Step 1: Now download the CM9 firmware package for Samsung Galaxy Gio.
Step 2: Put your device into recovery mode, but firstly turn it off.
Step 3: For entering recovery mode, hold the menu and power button together for sometime. Or watch the video bellow for bigger picture.
Step 4: In the recovery menu you need to select the option “Wipe Data/Factory reset” and then select “Wipe Cache Partition” and that will clear cache from your device.
Step 5: Once your phone in recovery mode, then select these options consecutively:
- Wipe Data/Factory reset
- Wipe Cache Partition (for clearing your phone's cache)
Step 7: In case something unwanted occurs during the process, like you are forced to close errors. Then repeat the process: enter your device into recovery mode, then wipe data or factory reset, followed with cache partition. And then choose ++++ GO Back ++++ and then choose reboot system now to restart your phone.