You certainly can. 

Resize

1. Select the pattern from the packaging design studio.
2. Click Resize in the Edit Pattern toolbar.
3. Use the sliders to adjust the pattern:
   • Scale (size)
   • Rotate
   • Horizontal position
   • Vertical position
4. When you're done, click Exit Pattern Editing to close the Edit Pattern toolbar.

Change the pattern colour

1. Select the pattern from the packaging design studio.
2. Select one of the pattern colours in the Edit Pattern toolbar.
3. Select a colour to replace it with.
4. Repeat for each colour in the pattern you want to change.
5. When you're done, click Exit Pattern Editing to close the Edit Pattern toolbar.

These steps can be followed on products such as Postal Boxes or Product Boxes.