First, remove the eyepiece. Next, attach the SLR camera adapter where the eyepiece would normally be attached to the telescope, and screw in a t-mount adapter to the opposite end of the SLR camera adapter. Now you can attach your camera to the t-mount and you are ready to begin taking pictures!
Note: Your camera will need to be in fully manual exposure mode, although some brands of camera may also work in aperture-priority autoexposure mode. Additionally, if there is a switch on the camera which chooses the focus mode, that switch must indicate manual focusing.