Roll up the cotton as wick, insert into the coil and make sure it is firm fit not too loose or too tight. Add a juice wick on top, trimmed both ends and saturate the wick with juices and filled up your tank. Reassemble all and mount it on your mod. Give a fast double draw and do not fire it first, allow it to sit for about a minute or 2.
you might also wanna take note that when you secure the stem and grommet back, there should be sufficient cotton to prevent too much inflow of juice into coil compartment.