Spritz with water, allow it to moisten the membrane up, take some tweezers and remove the shell, I’ve had to do this a few times. If you have a look at my blackberry by fastbuds diary i had a plant struggle as a sprout for about two weeks before taking off in to a beauty. Next time plant slightly deeper as they use the friction of going through the soil to naturally remove the shell and membrane. Until it’s yellow and shrivelled up it still has a chance. Looks nice and green to me, just have to give it a hand with the shell.