I can not remove the rear brake drum from a Lancer 2013

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.

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.

I've had similar issues when I replaced the rear brakes on my 2004 Toyota Yaris. Here are some things you can try:

• Most drum brakes have a slot on the backside that you can stick a flathead screwdriver in to undo the self adjuster. Doing so will pull back the brake shoes. Make sure the brake shoes are not stuck inside the brake drum. (This was my issue). If the drum is moving but doesn't get losse, this will most likely be the problem.
• Hit the drum (preferably with a rubber hammer) around the edges. If don't have a rubber hammer, you can use a metal hammer, but be gentel and use cardbord to dampen the impact. Unless if you're replacing the drum in which case don't bother with the cardboard.
• Some drums have threaded holes that you can screw a bolt in. The bolt will press against the hub, pulling off the drum.

What I ended up doing:

In my case the drum was loose, but not coming off, because the brake shoes had worn its way inside the brake drum, so the drum was stuck around the shoes. My drums don't have a slot to undo the self adjuster so I used an angle grinder to cut the drums in two.

Make sure to grind horizontal, not vertical, otherwise you can damage the brake cylinder. If you damage it, you must replace it.

Cutting the brake drum obviously means you have to replace it. If you grind horizontally, you will likely hit the brake shoes, meaning you have to replace those as well.