Lost a print head in my Phaser 850 and purchased one for replacement. Thought I could do it myself but in following the Dissambly guide I get to the point that I cannot lift it from it's two retaining connections. Easily removed the data harness, wiring harness and gound leads. Loosened completely the two mounting screws for the printhead. Now I'm stuck. Am having difficulty moving the printhead forward and have moved the cam to the three printhead positions. IS THERE A TRICK HERE THAT I AM MISSING. Any help would be appreciated. Thanks, Tom