You were smart to tell them to go away,,you can be new complete brake assemblies,which contain all new parts for about 100 dollars each.Just cut the brake wires at the hub,remove the 5 nuts holding the assembly and reinstall.
Most any heavy duty truck shop,rv dealer or trailer sales shop will have assemblies,chances are your brakes are 12 by 2 inch,buy a good name asembly ,something made in the USA ,Dexter,Lippert or Teksona.
I stay away from the Chinese stuff,they don’t last.
You can go on Google and watch many videos on installation from companies like Dexter,E trailer etc on installation,it’s not a hard job but you need to ensure you properly block your trailer while taking the wheels off
DO NOT jack the trailer up using a jack under the axles,place a 4 by 4 approx 4 ft long on top of you jack and jack your unit using the FRAME.Take one wheel off at a time,you will need a good heavy duty floor jack for this task as your unit is heavy,hook it up to your truck and lift the legs,this way you are not putting force against your trailer legs.Also place jack stands under the trailer frame once lifted,be safe.
While the brakes are off you can clean and inspect your bearings for wear and scratches,clean all the old grease out of the hubs,make sure you use the proper grease based on the manufacturers recommendation,if you have the book it will advise which grease to use based on manufacturer,NOT all grease will work on bearings,bearings get warm will running down the highway and wrong grease will melt ,also replace the bearing rear seal while you are at the job.
Good luck and let us know how you made out"...........
