When you click on the appropriate link on the MTH 141 home page e.g. "Download introductory worksheet", a dialog box appears. Indicate that you want to Open the file rather than Save to disk. Then press OK. Maple will start automatically with worksheet you selected ready for use.
In the unlikely event that the above procedure doesn't work and you see a screen full of gibberish, proceed as follows. Go to the File menu in the browser and save the .mws file using the Save As option with the appropriate file name and the .mws extension at any location you want. Now open the Maple program and tell Maple to open the file you saved.