The power cord hard to unplug from back of ...

step-1.
first switch off your tv unit and if possible switch off yuor main switch also
step-2.and pull out the plug bu holding the hand inth end of plug not in wire .
still you have the problem
follow step-1. and using wd 40 liqiud (available all electronic shops ) apply between wall socket and juntion of plug
and wait for five minites
then try step-2.
still you have the problem
finaly remove wall socket and try it now and remove the plug.