I am using Leaflet Slider, of Dennis Wilhelm, to try to show changes in data over a period of five years in a Leaflet map.

I am trying to get that when the user move the cursor over the slider, some marker disappear and some other appear. So far, I only get that the new marker appear on top of the old marker. 
So, my question is:

How can I remove markers when use Leaflet Slider to show changes over time? What changes I have to do in the original `SliderControl.js`? 

Thanks in advance!

Below is the link to Dennis Wilhelm's Leaflet Slider code: 

<https://github.com/dwilhelm89/LeafletSlider/blob/master/SliderControl.js>