How do I put my Orange sim card in my Vodafone phone?

I got a Vodafone mobile for christmas, but I would like to put my Orange sim card in it (so i dont have to change my number ect). Is this possible? How do i do it?How do I put my Orange sim card in my Vodafone phone?
It would help to know the model phones you have for specifics.



I'm from the U.S. and all our GSM phones are locked,

but from my understanding of phones sold across the pond they should be unlocked (in most cases) and very much possible.



Typically slide back off (dont wiggle, just puuuush) take out battery, find sim card, remove...



Repeat in reverse...