Butchers Method - Refilling the Disposable Pilot Varsity Fountain Pen - Other methods in the pinned comment.

Good Method:

https://www.mgtow.tv/v/ZqShKZ

Refill a disposable Pilot V Pen - Using Vacuum Filling - No Butchering the Feed and Nib

Instructions:


They said.

I like the smooth writing of Pilot Varsity, which is supposed to be a disposable fountain pen. I thought it's a waste to throw the pen away after using up the ink. So I looked up online and learned from a YouTube video that it's actually refillable and that we can refill it without pulling out the nib (thus can avoid potentially damaging the nib).

Basically it uses a vacuum method involving a 3ml syringe (which roughly has 10mm outer diameter) and a 3/8 inch PVC pipe (which roughly has a 9.5mm inner diameter).
Indeed this method worked beautifully: I successfully refilled the disposable fountain pen, without making any mess.

(The tube needs to be very short - with just 4 or 5 mm of clearance between the nib and the syringe.)