It's always advisable to remove the negative battery lead when carrying out
any electrical work to make the work area safe and prevent damage to
components. Use a good quality deep socket  of  the correct size to remove
the plugs as they are sometimes very tight.. Don't risk shearing them.
It's a good idea to apply a little copper anti-seize grease to the threads
when re-fitting.
Make sure you know the radio code just in case it's required after
re-connection of the battery.
KF

No you don't have to disconnect the battery, just make sure the
ignition is off. The only peculiarity is why they made it so damn
difficult to remove the one behind the pump!!!

can anybody tell why my cooling fans keep coming on when the temperature dial inside the car is displaying as normal