Spirit guides are not about spells. You cannot cast a spell, and "poof" spirit guide appears. A spirit guide is a spirit that has generally been with you since the beginning of your life. They can be considered "guardians", animals, or ancestors (family that have died). This means he or she has been around you this entire time. You must work on being able to sense and communicate with them, it doesn't come in a spell. You can do this within meditation, projection (Journeying, Astral Projection, Mental Projection, etc) or lucid dreaming. You cannot do this with things like ouija boards because this invites posers.
Do understand that they will not just manifest physically. They are there with you right now. Don't sense, see or hear them? That's what you have to work on.