i want the blower to turn off/on at set temps

What kinda disconnecting do i need to do, i no longer use the actual heating part of the furnace, and have no problem completely disabling it. I just don't know how to do it.

2, white and a red

i have an older coleman furnace in my home model # DGRT056AUA. I want to be able to control the blower with the thermostat without using the furnace itself to circulate air through the house and would like any help on how to do this. thanks