Tips 4 Markers: DIRECTIONS Replacing & Refilling: We use a pair of pliers and actually pull out the whole plastic end of the pen. Then we take out the ink holding core part from inside the pen and drip ink into each end, replace it into the pen and put the plastic end back on. That works well. Be sure it snaps all the way back into the pen. It's a little hard to pull at first but you won't break it. Just pull hard.