The one on the dash is coolant temp, its the one under the thermostat, if faulty its supposed to throw a code I believe.............
https://www.moparpartsgiant.com/part...5066779aa.html
The above link shows the location of most other sensors as well.
You will require a spanner of the correct size, simple unplug, unscrew, screw new one back in and plug back in...
What was the actual problem though ?? ............. It may just be a dirty/corroded connector, especially is you do engine washes..