removing front ABS sensor, help
 

I am trying ti remove the front ABS sensors on my 1986 420 sel for cleaning and inspection. My anti lock panel light has come on. I removed the 6mm? allen bolt but I still can't remove it, I can move it from side to side but I can't get it loose. I am afraid to pull to hard on it and don't want to damage it, is there a trick to this, any help would be thankful, as it is the wife's car and she is demanding me to fix it or no watching football on Sunday. Thanks Louis.