To release the modem Huawei E220 from any operator, you must follow these steps. No need to open the modem, modify or currently use SIM cards or other methods known to release mobile devices.
This has been tested with a Huawei E220 locked to Vodafone and Movistar blocked similar and operating properly.
The release of the device is done via Internet, payment via PayPal, on page Kulankendi .They offer free services for other devices, including a service "universal release" via IMEI. However, in this case we are interested in the release Huawei modem:
With this, the device is released, however no release or the firmware update restores old client connection therefore remains the ISP (and still necessary to use the program from the original ISP). Therefore, we must change the connection settings, specifically the APN, username and password, according to the new operator we will use:
Vodafone
Movistar
Simyo
Yoigo