Making a pinhole camera with your camera body is easy. Just procure a set of tubes. Mount one and cover the other end with aluminum foil. Fix the aluminum foil in place using masking tape. Punch a hole in the center of the aluminum foil cover with a sewing needle. You can experiment with different size holes and different tube lengths. You can mount, painted flat black, cardboard tubes to adjust pinhole distance. For your camera, a pinhole distance to sensor of 30mm, should be your fist experiment. Next elongate the distance. Each time you double the distance, the light level at the sensor decreases 4X. Conversely, halving the distance yields a 4X brighter image. Aluminum foil and sewing needles makes for nice clean holes. You can experiment with different hole sizes.
You can convert your camera to a pinhole camera without buying tubes or lens cap. You Jerry-Rig a lens cap to fit over your existing lens. This is accomplished using aluminum foil and masking tape. Place a piece of foil over your lens and tape it in place. A neat way to do this is to cut a circle out of aluminum foil, just big enough to completely cover a UV filter. Puncture it in the center with a sewing needle. Use double stick cellophane tape to hold it in place. An alternate method; buy a sacrificial lens cover. Cut a ¼ inch hole in its center. Paste aluminum foil over this larger hole. Pierce this foil with a sewing needle.
This works because the center of the camera lens has little figure (its shape at this point is practically flat glass). A pinhole overlay acts as if the lens and its aperture (Iris) do not exist. Thus the pinhole acts as a pinhole.