ooo claps her hands in glee - I know the answer to something!
(trust me living with 2 teenagers, this is a rare and to be celebrated occurrence
)
The inkpot - or holder thingy unscrews to reveal a gaggle of other nibs inside.
then in the middle of that is a wee silver thing that if you get someone with tiny fingers to help you - can be removed. If lack of small finger people is a problem - take out some of the nibs then it's easy.
This silver thingy has a wee notch that you grip the end of the nib with and it removes it from the pen.....
At this point refer to issue above and be very careful if you have the springy nib loaded as it can go boooooiing and land anywhere.....or where it is hardest to find
I'll have a go at getting 1 of my clover leaf kids shots to show you - might not work as there are lots of 1 Photosho PSD now.