how to change rear diff fluids???

Look at what kind off rears you have and then type them in google.
Put the word manual in your search and chances are you will get a document explaining it all.
(it also tell you what kind off oil to use and how much)

 

So far as how to....there is a plug in the housing on the bottom....closest to the ground....usually takes a 1/2 drive ratchet or pull handle. Oil drains out there it's the lowest point.....once drained reinstall plug....then on the back of the housing you will find another plug ....may take same ratchet or may take wrench ....remove and pump in there til starts to run out......

 

You can dig a hole in the ground to put a 5 gallon pail under the diff.

Sounds stupid but I know a guy that does it that way.

 

I drain and refill the hubs as well.

 

Have you priced gear oil lately? Last time I did it it cost me almost $200 for the gear oil

 

ya know,im just as cheap as the next guy.but changing the oil or diff fluid isnt going to break me.you spend all day gathering up the items needed to do the job.burned up at least 5 gallons of gas in the p/u,then got all nasty & greasy ,wife mad at ya for trackin up the floor in the kitchen and still blew over 200bucks on oil...THATS NOT RIGHT.....pay speedco so you dont have to now figure out what to do with all that burnt oil.thats called workin smarter not harder.you aint savin nuthin doin it yourself.repairs are a different story altogether.

 

Take the fill bolt/plug off first! Nothing like draining the oil and then having the fill plug seized from rust.

Learned that on a Land Rover. Lol