Same way glucose does. Lipids enter cells through channels similar to glucose ones, but designated for lipids instead of carbohydrates. Then lipase splits them into separate parts (fatty acids & glycerol I think). The glycerol can either be used to make pyruvic acid and the energy of breaking its bonds can be used to make ATP, or it can go to making glucose, which is stored for later use.
In this situation, the rabbit is the primary consumer because it feeds off the producer (grass) and is eaten by the secondary consumer (snake).
