Hi I have tried removing the drum on the car but it will not budge. I loosened the green screws, they popped out after they were only slightly turned. Please help....
2 ob-long holes are found on the back plate for the purpose of adjusting the brakes. Some cars have the hole cut into the Drum instead. Either way a flat-blade screwdriver is used to rotate a star-nut to enable the brake shoes to retract further, making drum removal possible. A pictorial diagram will point out the Adjuster. Take a photo of what you find once the Drum is removed. Do this on both sides. You'll know why at re-assembly time.
Some drums have a threaded hole so a bolt can be used to unfreeze the drum from the hub.
Clean around the hub/drum joint to remove any dirt or light rust first.
If it is really stuck then you may have to resort to a puller.
Posting a focused picture of what you are working with may help.