I used a mason drill bit on a cordless drill, slow speed, so I don't crack the pot. wet it every once in a while. so after making an outline, i used the drill to cut holes following the outline i've drawn. then using a hacksaw, with a cable blade, i carefully cut the clay pot. i used this method on xtra small, and huge clay pots. I did not cut the rim though, keep that intact, and just created a large enough hole for the fish to go inside, and then come back out. good luck!