HELP!! Problems with Skully!!PUHHLEAASSE!

[GirlyGirlBags]

 

I am feeling like such a moron!  I am trying to shape the neck section of the back of the Skully sweater and I keep messing it up.  I am to the point of knitting 30 stitches, join the second skein of yarn, and begin binding off to start the neck.  I don't know what I am doing wrong!  Do you immediatly start binding off with the new yarn? Please help because I've ripped out about two rows of stitches twice and I 'm about to frog the whole thing and burn it!   

Thanks!