It may be late in the evening here in the States, but for T-Mobile users, your time in the sun has finally arrived -- Android 4.0.3 is now available via Samsung Kies for the Galaxy S II. According to the carrier, the update won't be made available via an OTA download, which means that if you don't have a PC, you'd best shake down a friend at this late hour -- or, at least give 'em a call in the morning. In addition to Ice Cream Sandwich, the update is said to bring WiFi calling improvements and enhancements to the voicemail system. It'd also be wise to ensure that your phone's software is up-to-date before you begin, as Android 2.3.6 is a prerequisite of the upgrade. Ready to dive in? Just hop the source link for the complete set of instructions.