@ blinet,
Please
refer to this link for the detailed, step-by-step, unlock manual of Huawei U9200 phone model.
Please notice that this handset, as other Huawei Android sets, suppose to be connected to PC in a Fastboot mode in order to be unlocked. Detailed manuals on how to enter phone in Fastboot mode available
here.
P.S. in case if you're dealing with any difficulties to unlock phone, please post here full log file along with the detailed problem description.
Best Regards
GSMServer team