Change icon in slider

[AEK]

Im wondering how i can change the "icon" cg titel in a slider..


What i have is a slider for controling a light fixture the button is indicated with the following symbols: <   > but i need to change this to: -    +.
below you'll find the slider that we use for dimming the lights.


but i need to change this into the following with the slider function.


is there a way i can do this?

Thanks alot!

it is possible to change icon via css and base64. here is css example , it change slider position button, not arrows

Code:

.slider-handle{
padding: 0px 0px !important;
width:            61px !important;
height:           61px !important;
background-image: url("data:image/png;base64,iVBORw0K… (picture code)");
background-color: transparent !important;
border: 0px;
box-shadow: none !important;
}

here you can find more, but its on russian 
http://logicmachine.net.ru/solutions/rab...mi-stilej/