Not unless you readminister them so basically start again. If you change the questions but use the responses to the previous set of questions, then your data would not be valid. Doing so could land you in quite a bit of trouble. Unless you have time to start again (and a pool of respondents that are willing to fill them in again) I think your best option is to tell your supervisor that you've already got the data, and is there any alternative types of analysis you could do on it, that might help to meet their concerns about the original questionnaires.