install new print head on iP7220 - can't get old one out

iP 7220 prints come out with vertical banding  -  I found a 7220 print head on eBAY but can't get the old print head out.  I have watched you tube videos but my head doesn't release when I pull the lower color description band outwards.  I'm afraid pulling too hard will crack the plastic holding it in.  Right side seems to disengage but the left side of the "holder" doesn't move.  

Am I doing this correctly?   what are all the things I should know about reinstalling the iP7220 print head.

THANKS