Hi  all , with respect ...I'm not after any general or obvious health & safety advice here thank you !  I'm specifically asking....If any one has attempted to change out their Std K100 rear shock damping oil ( this is on the STANDARD  ---- "NONE Nivomat shock absorber" )as it reads & appears that to all intense & purpose's  this unit is none- serviceable !  
          I am very aware of the doe's & don't of working with sealed pressure vessels . I'm asking if any one has prior actually successfully done this , or am I gunna be the first to attempt it on an otherwise good condition 32 year old shock absorber . I expect to have to drill 2 small holes in the damper housing body .....1 at the @ highest practical damper point & the other @ the lowest practical damper body point, this to be able to both vent & drain then refill the damping oil .........then perhaps tap & thread  these holes so as to seal / plug them ......... or maybe even if required very carefully Tig Up the holes... if taping the threads are not possible . I'm asking for input here from any one thats actually done this ! & I'm asking to please maybe draw on your experiences & any issues that you may have had to overcome on this particular exercise & ask what grade / weight of oil you found best suited .  PLEASE REPLY WITH A PM TO ME....... THANK YOU for your help here !    

Look up RAD shocks he knows how to do it.
I have been working on cars and bikes for 60 years and in a professional capacity for many of those years and would not even consider doing what you want to do.
There are some jobs that you leave to the professionals and this is one of them.  They have made the cock ups that you would most likely make and are passing on the experience of the knowledge gained.

I’m with Rick on this one. RAD did a Koni for me. Excellent job and reasonable price.
I’d be thinking that your 32 year old shock would need more than just oil - seals, orifices etc. etc.

Bill

Hey Johny, off topic as far as the specificity of your question, but when I return to OZ in October the Eye-talian BiTubo rear shock I've got on the red '87 K100RS will be on the block for sale. It's a fine shock, a bit stiff for my weight with its mighty coil spring, but both 5 step damping and near-infinite pre-load adjustable - and fully rebuildable when needed. I've bought a Progressive 465 series to replace it with.

Two Wheels Better wrote:Hey Johny, off topic as far as the specificity of your question, but when I return to OZ in October the Eye-talian BiTubo rear shock I've got on the red '87 K100RS will be on the block for sale. It's a fine shock, a bit stiff for my weight with its mighty coil spring, but both 5 step damping and near-infinite pre-load adjustable - and fully rebuildable when needed. I've bought a Progressive 465 series to replace it with.

 Thanks for that. Upon your return here from Seattle please would get back to me on this. Thank you !

most car type double wall car shocks that I have attempted to repair failed miserably

firstly the seal around the push rod was knackered

attempts to seal a threaded hole in the shock proved fruitless after filling with oil ,  very hard to get it to seal correctly , I should have tried a fibre washer I guess .but the pressures under compression may have been the reason for failure

at least I tried !!!!