To change the question type you will need to open the questions.csv file (see example below) and in the column “answer type” change to desired answer type from the list above.
Save the file as a Comma-separated values (.csv) file. Depending on the software you may need to export it as a .csv file. You may now zip the file and re-upload (or upload the whole folder).
Note: when changing question type (for example from mapped to bool), you have to change questionid as well, just so they are different.
If you would like to find out how to change answers options choice see the article Changing question answers