Hi,
    I have a 7.4 2S 850mAH lipo that has a deans male connector, while the ESC has a deans already soldered on. Do I need to cut the LIPO wires at the JST connector and solder the deans to it or is there a way to remove the JST connector?

If at all you are cutting a word of caution. Cut the wires individually. Sometimes we make the mistake of cutting both the wires is on go. Thatz a sure way of having fireworks around.

Simply cut the wires of the battery one at a time and solder the cut wire before cutting the next, this will reduce the risk  short circuiting  by cutting both wires at the same time .
Sai