No Backup. Data is not super valuable. I have been watching YouTube videos and while dust and debris is an issue there are electronic degreasers/cleaners and dust/lint free cleaning wipes that the Pro's use and so long as I were clean my work area, where a N94 mask, cover my hair, and where gloves I can eliminate a lot of this. Besides if I am successful I will immediately back the disk up.
There are two issues that concern me.
1st) If that I have a donor disk that is the same part number manufactured 5 months later than mine. This issue is that I have found out that it is possible the heads have microchip in them that has a driver. I can only hope that they did not change the driver from when my was manufactured and the donor was manufactured.
2nd) You need a head comb to hold the head from the platter when you remove and replace the head. Since there are 5 platers (4TB drive) you cannot get around this. I cannot locate any in the US. I found one on EBAY that is from China but I am not sure I trust and one from Servia from a Company that custom makes them out of aluminum specifically or that drive model number but it is around $100 plus another $100 to ship it FEDEX. I can use Servia's mail service but they even do not recommend this as it could take months.
This is why I have been going on the forums and running into this do not touch or the world will end mentality. Even after I inform them I do not care if I do not have success I want to try it anyway. Also, it is usually one person that always responds and after I research them they are usually connected to repair/recovery facility . Something fishy here. Sound like job protection to me.
The whole point of a dust-free environment is prevent the introduction of particles that can result in a head crash. The fly height is 3 nanometres or less. The average distance between two molecules of air is 4 nanometres.
Data recovery pros like to give the impression that they walk around in bunny suits inside large air-conditioned, pressurised, dust-free "labs", but the reality is that 99% of them have a "clean cabinet" on a desk in a regular workshop.
If you want to make your own clean cabinet ...
https://forum.hddguru.com/viewtopic.php?p=204387#p204387
https://files.hddguru.com/download/Other stuff/DIY Clean Chamber V2/ (plans and drawings)
Your observation that "the heads have [a] microchip in them that has a driver" probably refers to the preamp. Generally the DR pros do try to match the preamp, but they don't just suck-it-and-see. Depending on the model, you can usually determine what preamp it uses by referring to the label or ROM or barcode sticker or terminal log or other identifiers.
If you have a 3D printer, there are free plans for making your own head comb.
https://opensource-data-recovery-tools.com/hardware.php
https://forum.hddguru.com/viewtopic.php?p=298006#p298006
https://disk.yandex.ru/d/XG-50CoK8hEIQQ (plans and drawings)
Certain models need extra precautions to prevent data loss after a head swap. For example, SMR HDDs are particularly critical. You need to disable writing (at the hardware level?) for these models.
In some cases you need to transfer head "adaptives" from donor to patient. These are unique, drive specific calibration data.
Headstack matching for Western Digital:
https://www.hddoracle.com/viewtopic.php?f=86&t=1036