There are a few threads on this already if you look back through this Health sub-forum, somewhere?!
The main points for treatment are firstly vet assessment of the hocks, and the bones and tendons of the feet, as chronic sore hocks can cause deformity to the tendons in severe cases and infection in the skin can spread to the bones of the feet and cause osteomyelitis. Not saying that your bun has this....this is just one of the long-term risks, so for this reason vet assessment is essential.
Normal treatment is often firstly pain relief if the hock is very inflammed and painful when weight bearing using anti-inflammatories - Metacam.
Antibiotics prophylatically in some cases to prevent any infection reaching the bones of the feet - depends on extent of sore hock (+probiotic)
A review of living environment - wire bottom cages, hard floors, abrasive surfaces, wood shavings are all considered to exacerbate the condition, as does wet/soiled litter. Other risks factors are obesity, lack of exercise and general poor health.
Long toenails also make the problem worse so keep nails well trimmed.
Somewhere deep bedded to rest up is very important - a lot of people find that the best thing for this is deep bedded hay. I found veterinary bedding very useful in our case, padded underneath to increase flexibility of the surface, as vet beds distribute weight/pressure evenly and sore hocks are pressure sores effectively. You need to experiment and find what works best for your bunny and where they seem most comfortable.
A soft area to exercise on is also important - a soft lawn/grass is very helpful if you have this as opposed to hard floors/concrete etc. Excericse helps circulation and healing.
Some people like to bandage the feet, others leave them open to the air, it depends, some breeds have less guard hairs on the sole of the foot and so in these cases bandaging can help. Some people find applying creams helpful. We decided not as it can squash any surrounding fur that helps act as a friction cushion and make the problem worse. Although keeping wounds wet promotes granulation tissue/healing, on weight bearing areas e.g. feet, this can cause the sores to break easily and get infected.
Apparently aloe vera gel can be soothing.
In our case we chose to not put anything on at all for fear of making things worse and kept our bun on a deep bedded and soft environment alongside pain relief/anti-inflammatories and antibiotics, it was very successful. But sore hocks are notoriously difficult to treat so it's all trial and error really and personal choice. I definitely recommend a vet visit though. Good luck