Be sure to check the alignment of the wheels before you install the new axles. I did not, and one of the two axles is so badly out of line that it chewed about a third of the tread off in about 2000 miles. Unfortunately, the trailer was not used heavily and it took some time for the problem to manifest itself. Tried to get the axles aligned but instead got a got a line from the dealer on how much other work needed to be done before the alignment could be done. I declined.
Not sure what I will do now, but wish I had not assumed that new axles would have the proper toe-in.
Regarding the weight of the axles, I made up a "C" shaped frame on 3 or 4" casters that supported the axles under the swing arms. Then it was a simple matter to roll the axle under the trailer and elevate it into position with a floor jack.
4CU Charter Member
AIR # 13858, WBCCI # 2420