Rough Around The Edges (RATE) Retractable Pen Mod Tutorial

Personal retractable mod I made and posted on reddit.
Some people wanted a tutorial so here is my first ever mod tutorial.
Parts Needed:
Pilot G3 (psershop.com/s...)
Pilot G2 (psershop.com/s...)
Pilot better retractable fine (www.amazon.com...)
Dong-A Anyball Pen (www.jetpens.co...)
Spare Inktube
DR GRIP (Any clear Grip)
Metal weight ring
Optional:
Airfit RIngs x2
Inserts