Because of the design of a Scotty axle, changing a Scotty tire is a little different than most. You have to jack the trailer up on both sides so the axle drops down to lower the wheels.

Park trailer on a flat level location where ground is firm. Block your tires and
loosen the lug nuts. Lower the tongue as far down as it goes.

Place your jack under one rail and jack up as high as it will go and then raise
your jackstand up to that level. Do the same on the opposite side. Repeat until you have
Scotty raised high enough to remove tires. Be safe and use jacks intended for holding
a trailer safely in the air. Do not allow pets or small children close by.

An SUV version of the jackstand that will raise 21" works, but you may need
to put a couple of pieces of 2x10 or 2x12 under them for extra stability, depending
upon the surface under your jack, not shown in this picture.

When you have both wheels well off the ground, raise your trailer tongue
back up, which will raise the wheels even higher and allow the
axle to drop so you may remove either or both of your wheels!