I figure that the Koi are small, as a 36 gallon aquarium is very small.
The main thing is that the water temperature be close to the water in the pond, if is much different do this, put the Koi on a strong clear plastic bag, such a freezer bag leave the top open, so they get oxygen, and suspend the bag over the pond for about 20 minutes, after that check and see if the water is almost like the one in the pond, if is close to it put them in, they should be OK.
If you do not have a net, to catch then use a lady slip or some soft like material, rinse it good so it will not have any soap residue, make it like a bag, not too deep, (that if the Koi are small OK), and you will be able to transport them to their new home.
By the way how big are they?.
Good Luck
Elvira-Elvi2004.