When you're using your stick for the first time it can be a little tricky to push up because the ingredients are a bit stuck to the tube. So the very first time you push it up it does require a bit more effort, but after that it will slide up and down in its tube easily.
2-3 Millimeters is all you really need to expose, If you accidentally push it up too far just gently ease it back down with the palm of your hand.
Step1, Before applying too much force try holding it in your hands for a minute to warm the tube and soften the deodorant inside a bit - Or if you have really cold hands like some of us in the Happy Shed this winter, place the whole stick under your armpit for a minute :-)
Step2: You can then put your stick top down on a flat surface and push steadily. If your stick is particularly stubborn place your thumb to one side of the base circle to get a little movement and then you should be able to push evenly from there:-)