Lens Modification - Vivitar 120-600mm

[niceguisuku]

Hi all,

I am new here. Forgive me if i posted to wrong forum.

I have a old lens Koboron 120-600mm f/5.6-8 with OM Mount and want to convert it to Nikon F Mount. This was sold by Vivitar in USA.The link to the lens with AI-S mount is shown below.

Vivitar 120-600mm Zoom

I came across the following site.

Olympus OM lens for Nikon cameras

I would like to know what are all the modifications listed on the site that can be done on this lens to fit it to Nikon DSLRs?

Thanks
Sukumar