Bifold door pin cap replacement

A quick learner from Brooklyn says:
Pin Caps on 2 metal bi-fold doors with mirror-fronts in our home have become distorted and it is hard to open/close the doors. I bought some plastic items from your website on what I guessed to be the right products but I have a few quandaries.

The attached pictures and dimensional data show the top pin & cap - the bottom door pins, dimensions and spaces are identical. I can extract the door-leaf from the bottom track but I cannot remove the "old cap" due to pressure on the plastic for over 25+ years. While the pins appear to be in decent shape, I don't mind if I need to replace them. However, I would like, if possible to accomplish the replacements without removing the entire doors from the closet - my fear is potential damage to the mirrored front-faces.

Among other plastic parts, I previously purchased 21-110 door pin caps. If need be I can take a hack-saw and cut the existing pin(s) and then attempt to put things together by inserting new pins, springs, etc. and cap without removing the door completely. In any case, what in your expert opinion would be the best-fit replacement products for this undertaking.

Thanks for your consideration. As an aside, I am quite handy with my hands and tools
User submitted photos of bi-fold door hardware.
Profile picture of Paul
Paul from SWISCO responded:
Your mirror door guide pin assembly looks like it was custom made. The way the pin and spring are locked in, I would not cut the pin. Instead, just replace the nylon cap. I see your tried three different types. The most common type that is used for mirror doors is the 21-109. Leaving the door up, I would cut off the old nylon cap and force on the new cap.
21-105 : Bifold Door Pin Cap
Bifold Door Pin Cap
21-109 : Bifold Door Pin Cap
Bifold Door Pin Cap
21-110 : Bifold Door Pin Cap
Bifold Door Pin Cap
21-150 : 1/4
1/4" Nylinder
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