Thanks, guys, epecially Pete... I know where to start now.
So i'm thinking this: each weapon has a 'value'.
So if current_weapon = 1 then delete the current weapon and place Weapon 1.
I think i will need to store another variable second_weapon. When the key is pressed to switch, the values of these variables swap.
To destroy the weapons I have a condition system global variable if current_weapon does not equal (1, for example) then for turret1 play animation put away then destroy the instance.
To create the instance i would want it to wait until the animation 'put away' of the gun is finished before the 'take out' starts. I am not sure how to handle this. Any ideas?