use my canon speedlite as a flash off the camera

There are several ways to to do a remote trigger of the flash. 

But before we go there, we need to consider that the Canon Speedlite probably controls the flash intensity based on the amount of light that the flash 'sees' coming back (reflected) from the subject. 

Whan the flash is not on the camera, the distance from the flash to the subject will be different from the distance from the camera to the subject.  As a result, the image will probably not be properly exposed. 

--Martin