Steel coolant pipe replacement

A mechanic has tried to remove steel cooling pipe above the gearbox and tells me the only way to remove it is to take the gearbox out. I find this hard to believe as it is a 10mm/12mm steel pipe approx 200mm long (it is the pipe that has two y-shaped smaller pipes coming off it). Surely Mitsubushi would not have designed it so the only way to remove the cooling pipe is removing the gearbox. Thanks for your help.