my rear diff fluid is like mud. Is there and I need to replace my seal where can i get step by step with a visual first time doing it or should I get a pro to do it

 

Welcome aboard. I guess i would inspect the seals and bearings first to see if you see and external oil leaking or axle movemet side by side.. If all good then IMO i would change oil and check the vent line[small black hose on top] to see it is off or broken.

 

Check the rubber boot between the engine and rear end. If the boot is torn water can get down the driveshift tube and into the rear diff.