I have a kiddy pool--specifically, a heavy plastic Step2 pool. The construction is probably more than simple plastic because this pool has been in service for many summers and has tolerated just as many winters outside. I was going to send it to the dump until I realized I could turn it into a raised garden. I need only enough space for a few tomato and cucumber plants. I plan to fill it with topsoil and I am concerned about adequate drainage. I thought about drilling many holes in the bottom, but then I decided I prefer to remove most of the bottom so the plants won't be in a container because the pool would be essentially sides and a couple inches of the bottom next to the sides for stability. I am asking what tool I should use to remove most of the pool bottom. I thought about taking a hatchet to it but I don't want to risk cracking the sides. What should I use to cut away most of the bottom, while protecting the integrity of the sides?

Thanks for any offered advice.