Attempting to change battery, but the core unit will not budge

Attempting to remove core unit (step #7) in my Samsung Galaxy Watch to replace the battery. The steps online seem to suggest that the core should just lift out. I have double checked the steps, and have done everything listed. The core will not budge. It is almost as though it is glued. I’m worried to force it too hard for fear that I will permanently damage it. Has anyone else experienced this, and does anyone have suggestions for getting past this step. Many thanks!