Samyang Rokinon Bower 35mm 1.4 focus slack

Hi,
I have a little slack issue with the focus of my lens 35mm 1.4 Samyang/Rokinon/Bower (Canon mount). The back part of the lens (close to the sensor) move when the lens rotate from up to down. Also, the same part does not move when I rotate slightly the focus ring (back and forth), but move when I make longer rotation.

I found two DIY solution
1. https://www.flickr.com …861364424/in/ph​otostream/
I don't exactly get its instructions, there is some vocabulary issue, and not many photos.

2. http://www.noiseandpic​tures.com …xed-or-modified-gear.html
The solution is for the 24mm, but look like the same problem, I guess same/similar solution could work.

Which path would you take?

Best regards,

3. A third solution is to play with the front of the lens
https://www.flickr.com …6308509/7215763​9547797944

Again, which way would you go?

Best reegards,

This is a clear video of the symptom.
https://www.youtube.co​m/watch?v=LuQGzJTVaj0

It turns no problem on a unidirectional stretch, but play when you switch direction.

Best regards,

My Samyang 14 2.8 is pretty horrible for this. I chalk it up to poor design and it is a reason I'm strongly resisting ever buying a Samyang/Rokinon lens again (I really want a 24 1.4 for astro work but just can't make myself do it right now).

No comment on the "fixes". I don't generally take my lenses apart so it is beyond my skill level/risk tolerance.

Seems like it wouldn't be a huge engineering stretch to make a less sloppy focus system.

rant over.

Let us know what fix you try and how it works.