If your mint plant has grown out to the sides of the pot, like this one, you may want to divide it and re-pot to grow several healthier looking plants.
Mint grows outwards at the roots, which will naturally push to the edges of a pot. From the outer roots, the plant puts up new shoots leaving the original centre of the plant to go woody and die off, which is what you can see here with the bare centre and growth at the outer edges.
At this point, you can turn up the pot and using a spade, cut the root ball into several sections and replant them in new pots. You can be fairly brutal, as mint is a vigorous grower! For a pot this size, we might cut the edges of the root ball into 5 parts, as an example, and discard the centre where there is little active growth.
The alternative is to get rid of it and start all over again with new plants, but there is nothing to stop you from keeping mint like this going for several years.