Need help moving tv off wall mount to install hdmi cord

[Ryan804va]

Need help moving tv off wall mount of 2009 3300rlb Sundance heartland 5th wheel to put in hdmi cord don’t know how to move the tv out to give me enough space to plug in a hdmi cord smh

 

[david-steph2018]

In our Road Warrior it is easier to remove the entire backing board, then flip it over and take the tv off. With the large TV, a 55" factory installed, I cannot get my hands under it to loosen the mounting screws. So, I take the 4 screws for the mounting board out.