If you feed small amounts then if you stick with Alfalfa based pellets follow the % of fiber, protein and fat I listed. Oxbow Alfalfa based pellets (Bunny Basic 15/23) is the only Alfalfa based pellets with that much Fiber. In other brands, you'd have to get Timothy for getting that amount of Fiber. Here is how to make a change in brand pellets:
For example, if your rabbit eats 1/4 cup of pellets a day do the following:
Day 1 - 5: 1 cup old brand - 1/4 cup new
Day 6 - 10: 3/4 cup old brand - 1/2 cup new
Day 11 - 15: 1/2 cup old brand - 3/4 cup new
Day 16 - 20: 1/4 cup old brand - 1 cup new
Day 21 Switched over to new food
From this mix scoop out their daily feed allotment. Some animals are pickier than others and will literally eat around the new pellet. If your animal does this, be patient. There is always a small percentage of animals that will refuse any changes and test the will and stubbornness of the owner.
Let me know how it goes!