After filling your tin with water and freezing it. Remove, lay on a towel and get your screwdriver and hammer ready.
Punch holes into the tin as desired and don't forget to punch a side door so you can pop candles inside.
Once finished, leave it outside so the water melts and you're left with a holey tin
Ta-da!! Your new lantern awaits you
I descended the tin making the holes bigger as I went but you can do whatever you want. Go crazy!