That depends. HDMI is Audio and Video, and unless your device allows you to route the audio channel into another form, you can't do any sort of audio routing while on HDMI.
It looks like digital audio is supported, so audio is likely able to be routed to that, but I don't know if you can route audio from composite stereo, while still having HDMI plugged in like you can on a PS3.
If you can route audio to composite stereo, all you need is a few connector adapters and wires. The Red and White cables are your Left and Right sound. You'll want a
Stereo to 3.5mm cable
with male and female ends appropriated to what you need. They normally go for $2-$5 on eBay and Amazon. Don't buy from China or you'll wait 15 days.
If your Wireless headset is 2.4ghz or other, I'm sure you'll know what to do as far as connecting goes. If your headset is Bluetooth, you'll need a transmitter to compliment your sink (Headphones). If Bluetooth is the case, I'll recommend one of these:
http://www.amazon.com/dp/B00DQUNODQ...TF8&colid=26BV3J9GD8Q8P&coliid=I3PSVG3FNKA0L6
They're versatile, cheap price vs quality, and highly rated.
You should test if you can separate audio to a different output before you make any purchases. And you'll need to be aware of any potential audio to video lag that might come out of using Bluetooth or separating audio from hdmi. AD2P Bluetooth can be milliseconds longer than video to varying degrees, so you might not notice a de-sync, not mind de-sync, or de-sync can be so bad it'll render video-based activities useless. I can only tell you the tools you'll might need, the rest is up to you.
Alternatively it seems, you can buy an optical audio cable ($4 on Amazon), and then buy a converting device that will input optical signal and output to analog signal if composite routing isn't an option, but still needing a Stereo to 3.5mm cable will be needed, as well as the BT transmitter if your headphones should need it, and likely another power source to power the converter (An empty wall outlet or hopefully USB from TV).