How much to replace three sets of window hinges

There is many options with hinges, so first we need to make sure this type available in the market. It can be dangerous to work alone with this, because if some hinges are broken then someone should hold the window while replacement process taken place. Should not take more than 1-2 hours per window, can be done by handyman if have experience

Have done many jobs like this in the past. As long as the individual is confident then it's a 1 person job. But ask the handyman first if he/she is confident to do this job.