How difficult a hernia mesh removal surgery is?

Can be very involved. In any location it is difficult ; less so in groin position but ventral hernia infected mesh can become a big procedure especially if bowel is adherent to it.
Difficult. Usually when mesh has to be removed, it is difficult to bring the tissues together unless another mesh is used such as a biologic. There is also an increased risk of recurrent hernia, infection, and nerve injury.