You get holes in a glass tank by drilling or cutting them with diamond coated bits. This is obviously not for the faint hearted, but many people do it sucessfully. You do have to learn the technique first.

I use a continuous water change system, with a small trickle of water constantly coming in and an overflow taking care of keeping the water level constant. I run the water though an activated carbon filter, made for "whole house filtration" of drinking water, to eliminate much of the chlorine. I have no idea if it is working or not, but I haven't had any problems that I can blame on chlorine. My system replaces about half of the tank water a week. If you use a plumbed in water change system that only works when you turn it on, you can just add the dechlorinator as the replacement water fill starts. That's how I do regular water changes.