I went today and get the grassland pellets by zoomed. My tortoise hasn't really touched them. But what I'm considering doing is chopping or grinding them up and mixing them in with his little salad of greens I make him every day.
Tortoises are creatures of habit. They eat what they are used to eating. Seldom will they just walk up and eat a plate of something they haven't seen before, and most of them don't like plain Grassland pellets. Few breeders introduce them to Grassland pellets as hatchlings.
The way I like to use the ZooMed stuff is to start with just a small piece of one pellet. Soak it until it turns to mush. It won't take but a minute. Then mix in that tiny amount of mush with the day's greens thoroughly. It might take a few days or weeks to really get him used to the new smell and taste if the breeder didn't do this work for you. When he seems to eat it all normally, you can begin adding a little more. Maybe bump up to half a pellet. Eventually bump up to one full pellet. When your tortoise gets bigger in a year or so, you can use a handful of pellets. Etc...