How does the toe kick attach to these cabinets? I see in the specs that it lists a toe kick can work with it, but I'm not sure how it connects.

Please check the assembly instructions which you can find on Lowes.com for these details. They are attached with clip the go onto the legs, which are included in ever base cabinet. The toe kick must be purchased separately. I thank you for your interest and please let us know if there is anything else that you require.