it is fairly simple .... but the fact that you are even asking about this repair kind of implies that maybe you do not normally do this kind of stuff? It is ok ....
find a person who works on their own cars that could do it for you if you are trying to save $$$ .... this is not major surgery at all .... a shop will charge you about an hour labor probably ....
there are also different grades of quality in the replacement unit you choose ..... from very cheap .. to about $250 for a Bosh unit .... you will get what you pay for ....
I put the Bosh on mine cuz it is also a 4x4 and I am sometimes way the heck out in the wilderness with the truck .... it would be a disaster to have a break-down that far out .....