Just recently i did complete disassembly to change trigger guard. What can i say, it is not easy, i was using
this video in Russian for T10 (traumatic pistol based on K100).
You just need to make gun half-cocked and pull out safety lever.
But i did it as part of full dissasembly when both pins which are holding trigger group (complete assembly on metal insert) in a plastic frame were taken out. Looks like all trigger part need to be pull up a bit.
This is the exact video you need to see. It is clearly visible that guy is pushing up half cocked hammer with a thumb while taking out safety lever, good luck!