Oh, I see... well in that case, it would probably be a good idea to discharge the TV if you have a discharge tool, and if you feel somewhat comfortable doing it. I really don't know if you have to, but it would be the safest thing.
As you can see in my project, I just removed the rear case of the TV, modded it, then stuck it right back on then inserted the whole TV in my cabinet. I thought about fully decasing, but I figured it would be a lot safer to keep it in the case. And it worked out really well because the bezel covers up anything that gives it away as a TV (power button, volume button, etc.)
If the TV will go in the cabinet fully encased, you could just make a bezel that would cover everything except the screen.
There was some guy who did the same thing you want to do, first he cut the speakers off, and put it in the cab. Then he went ahead and fully decased it and attached the circuit board on the inside shelf of the cabinet.
http://www.willcoxonline.com/mame/It does not say if he discharged the TV first or not, perhaps you could get in touch with him.