First of all, you need to go to a formal place to do it. There will never be such a problem in a formal place.

Secondly, in this case, you'd better ask him for compensation, because his technical problems lead to your friend's different eyes now.

Third, if your friend repairs it, he will have to wait six months at the earliest.

Fourth, there is no effective way to adjust the cut part, just like cutting hair. The cut part has to grow before it can be trimmed, so there are two methods so far, 1. That is to say, the two sides are adjusted the same, and the long ones are adjusted shorter, so that the two eyes can achieve similar visual effects. 2. Wait until the short ones grow.