Nikon 180/2.8 AI focusing is stiff

[ColdEye]

So I recently got this lens, glass is very clean, only issue is the focusing is pretty stiff. Do I have to completely dismantle the lens to get to the helicoid to re-grease it? The only suitable grease I have here is HelimaxXP which I have used on a few lenses before. I am trying to look online for a schematic or guide for this lens but I cant find one. I want this to be project for the upcoming rainy weekend. As for tools I do have some JIS screwdrivers.

 

[gorbas]

https://richardhaw.com/2017/05/21/repair-nikkor-p-c-180mm-f2-8-auto/