PUZZLE 037 Tails of the Unexpected

There's been an incident at a farm where all of the cows have disappeared.
According to a witness, a UFO sucked them all up and some aliens came out.
Why is anybody's guess, but now you need to place an alien in each of the spaces where there is currently a cow.
Touch a cow to suck it up into the UFO and swap it with an alien, and vice versa.
The creature coming down from the UFO will take the other empty space.

Hint 1

There are several ways to do this.
Let's take an example.
First, select the cows in order starting from the bottom, and turn them all into aliens.

Hint 2

Continuing on from hint one...
When they are all aliens, select the bottom alien to suck it back up into the UFO and swap it with a cow.

Hint 3

Continuing on from hint two...
Select the bottom alien again.

Super Hint

Continuing on from hint three...
Then just select the two cows.
Select them in order, starting from the top.

Answer for 'Tails of the Unexpected'

The answer is as follows.

1. Choose the leftmost cow.
2. Choose the leftmost cow.
3. Choose the leftmost cow.
4. Choose the leftmost cow.
5. Choose the leftmost alien.
6. Choose the rightmost alien.
7. Choose the rightmost cow.
8. Choose the leftmost cow.