You can adjust the handbrake at both ends. If you have slack in the cable then just tighten it up on the cable to take the slack out, personally I prefer to adjust it on the drums and then adjust the cable but that involves taking the drums off.
If you pull the handbrake on a bit you can see a 10mm nut on a threaded bar and you can get in with a deep 10mm socket and an extension to adjust it.