How do you activate the 4-wheel high drive? It is push button activated.?

When i press the orange part of the button i can hear it engage and it goes into 4-low. When i press the green part of the button i cannot hear it do anything and when i put it in drive it is still in 4-low. I have asked the previous owner how to do this and he said to put it in neutral, press the orange button then press the green button. I have tried this but it stays in 4-low. Any suggestions?|||I was told once that the way to disengage 4 wheel low is to take the vehicle out of 4 wheel low using the button and then put your vehicle in reverse and back it up about 20 feet or so. It works with my Ford Expedition.|||What type of vehicle ?? Try the owners manual or the website of the manufacturer|||In my 4wd truck, I shift the transfer case lever.