How change difficult from hard to medium?

Unfortunately you can't.

yes, sadly, you can`t.
Coopordie is running with "difficult" skill only.
If difficult is too hard for you, here are some useful tips ->
When a chick shoots her rocket out, strafe left or right (at least a bit) to dodge the rocket.
When a gunner spits his grenades out and you`re close to him, strafe as well.
About a berseker (this strogg is melee only) -> when he starts to swing his hand (and is going to hit ya), move away a bit.
Tank -> when you see him spitting rockets or lasers out, better take cover.
You can also "črush" him with a chaingun when you`re on duo or trio.
Mutant -> when he jumps on you -> strafe.
Medic (the beast that avanges dead stroggos). Strafe as well (I usually strafe aroudn him and shoot him).
Parasites -> jump on it`s back, then shoot it, or take cover when it spits it`s tongue out.
Also, when you shoot a stroggo, it gets stunned, so you might have an advantage on killing it. (Like gunner with super shotgun -> when you`re close to him and shoot with SS for first time, he gets stunned, and when you shoot for second time, he dies. But thats only when youre very close to him.)
Gladiator (the railgunner) -> when it shoots his rails, strafe. When he swings his "scissors", move like against a berseker.
Boss (giant flying monster) -> better use chaingun and quad damage against him. But if you dont -> when he spits his rockets out, move away (like for 3 metres). When he shoots his chaingun, take cover from it.
"Flying Bucket' -> when it shoots its lasers, strafe and shoot.
Those little flyingthingies wiht melee as well -> just shoot it. I`m too lazy to explain.
Makron? Better use quad damage and invl on it (you can get the inv from 4th unit in caves, not far from those lasers that destroy the rocks DOWNSTAIRS. It`s like you shoot those two shitz, then a way opens, and when you go, at the end -> shot the cave, so there will be an inv. (Invulnerability or how do you spell it).
You can also do a corner-shoot on thse stroggos, but Andreil will explain that better.
Have fun!
Metal.

"Flying Bucket"
What's that? They throw an empty bucket at you, hoping to stick it on your head?



Oh, you.

Well yes, you can basically stick to the wall and use the commands "set hand 0" and "set hand 1" (eventually "set hand 2") to give your shooting point a small outset. Basically, if you're left handed - you will shoot a bit from the left. The same applies for the other handlinesses. (Yeah, I messed up the word quite much)