[bojan]

There are couple of ways to enlarge the image (zoom-in, or increase the focal length of the Newtonian optical system):
1) leave the objective of the camera where it was and use eyepiece (just as you would use your own eye instead of camera to look through the scope
2) With camera lens removed, use eyepiece projection (focus the image by moving the eyepiece out until the image is focussed)
3) With camera lens removed, use barlow lens instead of eyepiece
All this will be OK for planetary or Moon imaging.

There are adapters available (to start, sometimes just a bit of PVC pipe and sticky tape helps a lot.. depending on the individual taste, of course.)