Hello,
The HF swing jack with a caster can be clumsy for turning and moving a trailer, especially on soft ground. So I replaced the 5" hard plastic wheel with two 10" pneumatic wheels from HF ($6 ea). The video and its caption pretty much tells the tale. The axle was drilled in three places for hairpin clips to keep the wheels in position- at the outer ends, and another inside the wheel bracket to keep the axle in place for single wheel use. The towbar unscrews from the TEE on the axle when it's not needed.
https://www.youtube.com/watch?v=qxcBmNNdGrk