The temp sensor, is it easy to change (mine's a 97 XJ auto)

And to replace the oil pressure sending unit, does the oil need to be drained first or something, or is it just disconnecting the sensor, replace and reconnect?

 

Well now I have a whole new set of problems, the serpentine belt is off and the fan is dangling, I've been told its either the idler pulley or a seized water pump... Ruined gasparilla for me, everyone's gettin' crazy and I'm sulking hoping the tow truck driver was kind.