Don´t worry, not easy to achieve.Should be putting NSFW before you post these kind of pictures! Hehe
Beside the gear you need a very precise late or CNC-milling machine
as it is crucial to have no play.
Chris, anatech over at DIYAudio, was a service technician for most everything for years. He knew the cd players from the 80's and 90's inside out. He always used to praise the quality of the Nakamichi players.
There is nothing special about the Nakamichi transports.
Smaller manufacturers like Nakamichi relied on Toshiba / CEC, Sony and Philips as suppliers.
The first generation of Naks had the same Toshiba HOP-32 kind-of lasers that were in almost every good player,
from Toshiba over Kenwood to Denon. Optics were top notch and the heavy Toshiba laser
could be even mechanically aligned in three axis.
I think the RF-Opamp for the diodes was on the OPH-32 itself,
so the weak current from the photodiodes traveled a short distance before being amplified.
An Idea that was much later re-introduced by Sony with the KSS-240
The second gen of my Mac is a Sony KSS-123A, RF-Amp already on the Main PCB, so the current has
to travel about 15-20cm before being amplified. Eye-pattern becomes more noisy.
BTW, I had very bad experiences in real life with Chris, anatech.
I asked him to collaborate to develop a solution for exchanging laser-diodes and he agreed happily.
He would figure a routine, I would produce/mill the means needed.
So I did ship anatech a BU-1 transport from Germany to Canada, including 10 Sharp diodes.
I also sent him money to buy a Sony CDP-102 that has the same BU-1 transport for reference.
This was maybe two years before Manolomos published @ diyaudio his findings how to swap the diodes.
But he did nothing and also never took part in the discussions @diyaudio.
After 2 years of patient waiting I asked him to send me the BU-1 and the player back,
there was still some of my money left to cover the shipment.
He acted like a prima donna and played offended, never sent my belongings back, so...