stem removal on Mosel date 8315

HI I’m at the last point in this build, installing into the case, but I cant get the stem out while the watch is running. When I removed the temp stem at the beginning I had to pinch the movment with the tweezers to depress the button, but now with the dial and hands in place I cant get it to press in. it does feel quite stiff…

Does anyone have any advice on how to press the button in?