right click the boxplot and select the add-->data label-->individual data-->use label from column, then the data will be display including the max and min. You may remove the particular data display by just click on the data and delete.
To display the median or mean reference line to be displayed,
choose the label when tou are creating the box plot. Select the data label and choose the median in the lable check and use eight y value lable or label from the data collection.