This can be a dangerous operation, if not done properly, because the movement can fall with disastrous results. I advise you consult a professional before attempting this. However, if that's not possible, I have outlined the process below.
First never attempt to remove the hood without at least one weight being in place. The hood of most British grandfather clocks is removed by sliding it forward. Before sliding the hood forward, secure the glass door to prevent it from opening when the hood is lifted off.
Next remove the time side (right) weight and then remove the pendulum from the crutch. Because the movement is held in place by the downward force of the weights, when you remove the strike side (left) weight the movement is susceptible to falling. While you unhook the last weight, keep pressure on the weight cable and then remove the movement.
Many clock cases do not fasten the "seat-board" to the "case-cheeks". After the last weight is removed you can lift the movement, dial, and seat-board out of the clock.
Finally, with the clock movement secure, remove the hands and pull the four pins that fasten the dial to the front movement plate.
We have created the video below showing how to remove a clocks movement. Visit our YouTube channel to watch more videos. There you will find numerous tutorials covering topics like how to remove a clock's movement from the case, how to remove a clock's dial, and how to adjust a clock's beat.
Here is our YouTube Channel: TickTockTony