Ok i took a picture (sorry it sucks)
Get yourself a wire coat hanger and bend the end like in the other picture
below (make sure you leave the hanger long enough...
Then just reach through and use the V on the flange right up where the plastic pull chord is normally wrapped around the shaft and pull it back.
By the way the text on the pic below reads
top - ring that goes around shaft to manually pull back (this is probably snapped)
middle - plastic pull cord that goes back into door hinge area
bottom - this is the actuator arm which angles downwards just a little further back behing this text - and the actuator itself is directly below
Hope that helps
H