First time putting the string into one eyelet and just barely was out the other eyelet when i pressed the reload button by accident (should've removed the battery!). The short string got wound up inside and I couldn't pull the string out from the longer side. So I tried to remove the head by pushing the tabs but I can't pull the lower part of the head off to remove the string. Is there a "secret" to pushing the tabs? Why are they indented and not flush with the surface of the side of the lower head? Feels like I'm not pushing them in enough. Not ergonomically friendly?Help!