I replaced the switch only, didnt need the whole retrofit kit (which is expensive).
Im not sure if the switch will work temporarily if repaired, these switched are not repairable as far as I know, you may have a different type of switch.
Do you have an override button? The gear should go up if you put the gear lever in the up position and press the override button, since the override button bypasses this switch (do it in flight or on safe jacks only!).
Im not a mechanic but I am describing how we fixed the issue that I had. My gear wont retract below 100 KT (it should retract around 65KT).