It is not a particularly difficult do-it-yourself project. You will need a permit, parts (recessed cans, light bulbs, trim, wire, wire connectors, switch) should not cost more than $100. You will need some basic tools – at least a drywall knife and a drill (but your life would be easier with an electric cutting tool such as dremel or a small jigsaw).
The trickiest part is closing holes and finishing the drywall – especially if you have textured ceiling. You will need to make sure the patch is perfectly level with the ceiling, you will need to reproduce the texture and match the color.
Professionally done, this job will probably cost you $100/light just in labor.
