1. Create a new task
2. Create your first step by hitting the + at the bottom.
2a. Select Variable from the list that pops up
2b. Select Variable randomize from the list that pops up
2c. This is dependent on what you wish the keyword to be, in my case I went with %RANDOM.
2d. Should've prefaced this sooner, but you'll want to set-up your images like Untitled-1.png, Untitled-2.png. MIN refers to the lowest number you wish to start from, so 1. MAX refers to the highest number you wish to use, so 62.
3. Time to create your second step, hit the + at the bottom again.
3a. Select Display Action
3b. Select Set Wallpaper
3c. Navigate to where you have the wallpapers saved on your phone (i.e /sdcard/Pictures/Wallpapers/)
3d. Make sure when doing this that you set the image to be Untitled-%RANDOM.png - This allows the first step (randomize) to input the number it gets into this step, and thus sets a random wallpaper.
4. Assuming you have creation down now: + > Task > Wait
4a. Choose whatever amount of time you wish, I use 15 minutes.
5. + > Task > Goto
5a. Action Number
5b. Set number to 1, if it isn't by default
6. Hit the play button, and there you go. You now have your wallpaper rotation going.

MANUAL ROTATION TASK
Sometimes you wanna skip a wallpaper, so this comes in handy. Its pretty much the first two tasks above.
1. + > Variable > Randomize
1a. Set MIN and MAX Number, as well as keyword
2. + > Display Action > Set Wallpaper
2a. Set up the image location just like last time
3. That is it, hit the play button and you can now manually rotate your wallpaper at random.