Hello Dark Knight,
I have used a tilt bed trailer and come-alongs to both load and unload heavy machinery. The come-alongs (or winches) are attached at the base of the machine. The mill head is turned down and the table is lowered to lower the center of gravity for a safe move. Use strong tie-downs especially to keep the machine from sliding forward on a panic stop. Plywood under a machine helps keep them in place during a move.
Back the trailer into your shop/garage etc, tilt it down and winch the machine off. I have also anchored the machine with chains to a fixed post (or deadman) and driven the tilted trailer out from under it (slowly) !!!! Get a couple of stout friends to help in your move.
A pallet jack is also a handy way to move your mill around the shop. Thick wall pipe can be useful rollers to move the mill around on a concrete floor. I have used them on a dirt yard and it was a real bitch !!! We had to build a road-like surface of planks etc. The push was from a 2x12 plank and a 3/4 ton pick-up truck !!! The plank acts like a shuffle board stick at the machine's base.
Those 90 degree angle milling attachments are neet and SPENDY. It seems like everyone wants one. For the price I'd shop for a small horizontal mill !!! More machinery is always better (providing there is space available). Some small horizontal mills have become almost cult items like the Atlas-Clausing bench mills and are way over-priced today. I had one once and miss it.