I remember reading somewhere on FPN that someone was trying to turn their Vector rollerball into an FP but the lid wouldn't click closed. I found the solution last night as I wanted to turn my green rollerball into an FP so I could fill it with green ink!

You will need a rollerball and a FP. The pen surgery is on both the lids. There is a small sticker on the top of the lid, either silver or black. Take off the sticker and under it you will see a tiny screw. Unscrew it and a plastic tube thing will fall out, it is either black or white. This has a different shape in rollerball and FP lids so all you have to do is swap this plastic tube part over, screw it back in and replace the sticker. I hope that is clear and I hope the person who was asking about this some time ago sees it!

Thank you!!!!
Know I was one looking for a solution.
I will pick a victim from each group and see if I can make this work. Have a Stainless Steel RB than I'd like to use as a FP.

Oh great, I'm glad you saw this! Hope you can make it work. I have to confess it was not me but my father who found this out! We were both very surprised to find a screw in the lid. The pocket clip becomes loose but does not come off and it tightens back up when you replace the screw. Good luck!