As a follow-up, I pillaged the bearing from my xpedo mtb pedals and all went well. They were perfectly clean inside with the original grease in tact. Now I have to find a local source for the bearings - the official kit is crazy overpriced - especially with the outrageous shipping prices on top.
Thanks!
Some options in this thread…
I got mine from bearingboys - cost me £12 for the set.
That was 4 years ago though 
i got replacement bearing on amazon, they pretty cheap: 6700 and 686. just look at the number on the units and match. read up on “ABEC” ratings but pedals dont spinn that much so not really a factor unless you’re anal and just want the best.
Hello. I have favero bepro. Single side power meter, with look pedal.
I also have shimano spares pd-m520 and pd-m780 (xt series).
I knows I don’t have assioma but bepro, older model, but does anyone know if I can also do the swap? Do inner axles match? Or should I try to disassemble the bepro?
IDK about the Bepro versions, but on the Assioma pedals with pods, only specific Xpedo mtb pedals bodies will fit. I tried some other Xpedo mtb pedals and they did not fit. I’m sure Shimano pedal bodies wouldn’t fit my pedals either.
Any updates on using these pedals?
More then 1000km on them, still no problems.
Here a more professional way to modify them (I also used a CNC mill to get a smooth even surface)
https://www.trainerroad.com/forum/t/diy-assioma-duo-shi-in-gr500-flat-pedals-done-right/97601