To change the coil in your Arymi Gille tank, firstly hold the tank upright and grip the airflow on the tank. Unscrew the the top section from the airflow, as it you're going to fill the tank. This will remove the top of the tank with the coil attached.
Next, pull the plastic mouthpiece off. This will expose a top ring with three marks in different sections around it. Twist this marked ring slightly and it will loosen its grip on the the coil, so a gentle pull should remove the coil.
To insert a new coil firstly prime the top of the coil, which has the 'leg' sticking out, by putting a drop or two of liquid onto the end and waiting for it to soak in.
Then, sit the coil in the circle where the previous one was and slot the wire leg into the gap caused by loosening the top ring. With the coil slotted in, hold it in place and screw the top ring back down until it holds the coil firmly in place.
Finally, prime the rest of the coil by putting drops of vape juice on the exposed end and waiting for it to soak in, then screw the whole top cap back in place. Leave the filled tank to sit for around 15 minutes so that the liquid can soak into the length of the coil, and then you're ready to go.