1. Open Pro/DESKTOP
2. From the File menu select New
3. Choose Design
4. Select OK
5. Maximise the screens

1. From the Assembly menu select Add Component...
2. Open the component part base from your MyWork folder
3. To fix this first part in position right click in the modelling area and select Fix Component
4. Repeat steps 1 and 2 for the part back
5. You should new be able to select the back using the Select Part  tool and drag it around in the modelling area
6. You can also add the pre-drawn tube from the Palette 
7. If the Palette is not visible, select Palette... from the Tools menu
8. In the Palette click on the Parts tab and then drag the tube into the modelling area

1. Choose the Select Faces tool from the toolbar
2. Select the outer surface of the tube
3. Using the Shift key add the tube hole in the base to the selection
4. You can now Constrain these two surfaces by choosing Center Axes from the Assembly menu
5. If you now select the tube using the Select Part  tool, you can drag the tube around but it will be constrained to be concentric with the hole in the base
6. Constrain the vertical position of the tube by repeating steps 1 to 4 but this time select the bottom face of the tube and the bottom of the hole and select Mate from the Assembly menu (if you now try to drag the tube around, it can only rotate about its axis)
7. To fix the back in position you need to add 3 constraints - Mate the front face to the back face of the base Align the bottom face with the bottom face of the base and Align the right hand faces of the two parts

Advanced - Try adding and positioning two screws from the Parts Palette