Auschwitz: Liberated by the Soviet Army on January 27, 1945 Chelmno: Liberated by the Soviet Army on Janaury 17, 1945 Belzec: Abandoned by the Germans in January 1943 Majdanek: Liberated by the...
On entering camps the Allies had to:
Disarm any remaining guards and take them prisoner. Take immediate steps to prevent the spread of any dangerous infectious diseases. Give appropriate food and...
In most cases the SS guards fled (or tried to flee) when the Allies got close to the camps. The main difficulty for the Allies was usually reaching the camps, not the actual liberation.