Clean Lg Tv Smudge On Inside Of Tv Panel?

Smudge on inside of tv panel? - clean lg tv

I bought a Plasma TV LG 42PG20 and inside panel. Because the back of the screen, where I smudget can not reach certain angles are rather vague about it. Some angles to demonstrate this, I know this is not much, but there is a way to clean it without emptying my guarantee.