Stuck in 4WD low

[drumz]

I have a 1995 Explorer XLT V6 Automatic. This morning we awoke to snow so I took my son to school. After warming up for 5 minutes I switched it to 4wd low by mistake and then switched it to high but the light (and it) stayed in low. I tried changing it to 2 WD and 4WD High drive but it is still stuck in 4WD Low. So now, after being off for an hour I went back out and started it up with the switch in 4WD High. The 4WD light came on and so did the 4WD low and it stays like that no matter where I turn the dial.
Does anyone know the cause and or fix?
Thanks!

 

[drumz]

Fixed

Read through some posts and I wasn't putting it in neutral (I thought Park would do it seeing it meets the criteria - < 3mph).
So I put it in neutral and it worked!