Help with imei

I am almost a complete noob but i have a question which may be considered illegal... let me explain, I am from nigeria and data cost here is very expensive but not to blackberry. Many using MTK devices have been able to change their imei to that of blackberry and it work.... But i'VE tried many ways but seems not to help.... I have you xposed imei changer and efs professional but non help... my question is if there is any way i can delete my current imei so efs professional can help write a new one