it depends how much room you have to work with. the brass ones will need to be hammered into place the rubber ones are probably bolted in. had a car rust one out and i just put in a engine block heater in its place. easier to but in as it was right under the exhaust manifold.
JKURX Anvil, Auto, 4.10, Remote Start, Auto Temp Control, Dual Top, Engine Block Heater, 730N
Ordered on 3/1 VIN on 3/7 D1 on 3/21 F (PAINT) on 4/15 KZ 4/16 KZM 4/18 KZN 4/23 Delivered 4/28