There has been lots of confusion especially in the past on Minwoo’s mod

Tools: X-acto, Knife, Pliers, Scissors, Acetone and Cotton Balls, lots of them

I happened to own the mod and had the clarified version for the back cap and I still see a few blogs with it done wrong. With that, lets start with the tools

Parts:
-1 Pilot G3 (Metal ver.) (Cap, Metal tip)
-1 Gripmatic Mechanical Pencil (Tip, Grip)
-1 Pilot Dr. Grip HDG-50R (Tip, Grip)
-1 Dong-a Comssa (Cap)
-1 Pelikan Superpirat (Barrel)
-1 Sailor Gel (Grip) (Not shown in picture)
-1 Penwish ring (more commonly known as O-rings for Pipes in hardware)

1- Cut the nub off the G3 cap and sand as shown

2- Cut off only 1 block of Gripmatic grip

*Many were confused by this but a long time ago before Minwoo disappeared and removed his video, he had an annotation in his video and a while back in old UPSB there was a thread clarifying this. I still have the same Minwoo till this day. So I hope this clears up the confusion on this part

2- Remove the Rubber G3 piece in the cap and place the Gripmatic Tip inside the cap. The tip should hold in place by itself

3- Cut an insert at about 2.5 cm by 3.6 cm

I bet someone is bound to be unlucky to run into this problem

*A tip for when placing the insert inside the cap with the Gripmatic grip and not having the paper get crushed is to actually use thinner printer paper
I personally used white origami paper, but you could also try to shrink the Gripmatic Grip in a smaller cap for a day

4- After placing the Gripmatic tip and grip inside the Cap, I recommend putting the G3 tip in last

*I recommend just slowly pushing in the G3 Tip to prevent it from crushing the insert. You can use the G3 ink tube or even a chopstick to push it in slowly

5- Clean out your Superpirat using cotton balls and Acetone. I actually recommend using an X-acto knife to cut off the backplug

*Do not commit to cutting the whole backplug off, once you cut it and you can see the back plug sometimes you can pull out the whole plug
-If you can’t, then slowly cut out the blue parts of the back plug until you see the white sections of the body.

6- Your back plug should look like this where as much blue of the backplug is removed with the ink

7- Add some tape to the Superpirat on the backplug side and place the G3 cap. Then place your Comssa cap at the eraser side or the opposite side that you did not cut

8- Cut 2 Sailor Gel Rings for the Comssa Cap and the G3 Cap

9- Cut your Dr. Grip grip, the lip side of the Dr. Grip grip needs to be 2.5 cm, this is very important for this mod. Then cut the non lip side of the Dr. Grip Grip at 1.2 cm

10- Place the 2.5cm of Dr Grip Grip on the Comssa Cap and Dr Grip tip inside as shown

11- Place your Penwish Ring or O-ring inside the lip of the Dr Grip Grip inside like the image

12- Put your 1.2 cm of Dr. Grip grip reversed on the cap. The non cut part of the Dr. Grip grip should face towards the body when placed on the cap

Congrats! You have now completed Minwoo’s mod the way he did it originally! You can adjust how far the Dr. Grip Grip is placed on the mod to help the COG of the pen when spun. Some have said in the past the mod feels too unbalanced. Hopefully this will help with your outcome