Very little. Effectively all that is mechanically required to do is literally change the trigger to a single action only trigger. It will have dimensions that will not allow it to come far enough forward for the trigger bar to reset to the double action position. That's all. Just the one part.
This can be accomplished very easily. You don't even need to disassemble the sear cage. Really the only part you may find challenging is reinstalling the trigger return spring but even that is easily rendered simple with a Cajun Gun Works 2.5mm floating trigger pin (SKU is 75920, originally it was made for the SP-01 Phantom) to replace the factory trigger pin, which is a roll pin. That comes with a slave pin that really simplifies installation.
An aside, you can certainly do whatever you want to your own gun, but I echo Bret. Why do this? I have never ever understood why many want to do this. I can discern no advantage other than a different shape to the trigger but numerous double action triggers exist that still change the shape without losing double action function. Reset is not inherently improved, trigger pull weight is not affected, single action break is not changed, you could still carry it cocked and locked with the DA trigger. All that I see is the loss of double strike capability.
