This is only my second instructable, so I'm open to creative critisim. Hope you enjoy!
Thanks, tranoxx.

Step 1: Supplies

For this Instructable you will need:

1 cheap plastic pen, I used a Paper Mate Write Bros Ball Point Stick Pen (this Instructable will not work with a pen with a screw on top, you must be able to easily remove the top with pliers).

1 pocket knife with pliers and a knife, I used the Leatherman Blast.

Step 2: Take It Apart

Get your pocket knife and get out the pliers, now get your pen and pull off the top using the pliers. there should be some plastic that was under neath the pen body.

Step 3: Cut It Up

Next you want to get the knife from you pocket knife and start cutting the rim of plastic that was inside the body of the pen off. Be careful one knifes are sharp and two you do not want to cut the white plastic tube, thats where the ink is, if you cut it you'll have ink going every where. take you time and be careful.

Step 4: Put It Together

you've done most of the work now we just have to put it back together. Its easy just slide the part you cut off off and put the tip back on and your done! Now when someone opens the pen, the top will either stick in the cap or fall out.