Super easy if you have access to Minecraft: Xbox One Edition Achievements
.Does not require a fishing pole or anything like that.
There is a much much easier way to earn this achievement that doesn't require any special equipment besides the saddle and the pig.
Load up the Tutorial in the older version of Minecraft and save the world.
Import this saved Tutorial world into this version of Minecraft.
In the world, go forward out of the starting area, over the bridge, and take a left at the area that has wheat signs on it.
You'll find yourself in an area with a bunch of pens, including a pig pen with a couple of pigs in it. Just to the right of the pigs is a pair of gates to the horse area. There is a sign to the right of this that has a saddle in it. Mine this to get the saddle, and place the saddle on one of the pigs.
Now the setup: dig down underneath the pen
. You want dig out a 3 block high area underneath the pig pen. Once you've done this, enter the pen (I recommend closing the gate behind you), mount the saddled pig, then dig out the blocks underneath you.
The pig will fall, but survive, and the achievement should unlock.