How to remove a stamp hinge?

Hi. As far as I have looked in the web, stamp hinges are removed by wetting the stamp and trying to pull it out gently. Thing is I inherited a very old stamp collection with stamps that are almost 150 years old which are hinged and I don't want to damage them. Some stamps are 1850's, and I am a little nervous to remove the hinge of them because I don't want to rip them since they are so fragile. Can anyone give me some tips?