Mold discovered under the baseboards - how to remove it?

Can you recommend something, would you do it differently, any other tips?

The most important thing is, of course, to find the cause. Why is/was the moisture so high there? Was there a singular event, like a flood? Or is there a leak that continuously wets the floor/walls? Then: - Eliminate the cause - Dry (heat, ventilate, if necessary dry technically) - Renovate