The best time for re-potting any plant is generally Spring (March - May). As you see a little new growth, you know your plant is getting ready for the growing season so give it some space to grow.
Have good-quality potting soil ready. Increase the pot size by 1" - 2" depending on the shape of the root system. If roots are very entangled in a tight manner you may have to pre-wet the roots quite a bit before gently tearing them apart. If you have a lot of dead black dehydrated roots, clip them back.
If your pot doesn't have holes in the bottom for drainage, you will need to add gravel or clay shards in the bottom to keep the roots from rotting. Then add fresh soil to the bottom of the pot to allow the roots to start growing again. Place the plant in the pot keeping the planting level the same as the previous pot. Do not plant too deep.
Add new soil around the sides of the plant and gently tap the bottom of the pot on a hard surface to let the soil settle naturally. You may have to add more soil and then re-tap. When you water, this will also settle the soil.
Now sit back and watch it grow!