Jimmy Dazzler can be found in a house to the west of the Flying Horse Inn in East Ardougne. His house is marked by a red star on the minimap. He needs a house cleared of rats in an unofficial capacity so as not to tarnish his client's reputation; to this end you will need to sneak around the house unnoticed, avoiding the guards who will think you are an intruder. Jimmy will give you directions to follow to the house. When you choose to follow them (you don't have to go anywhere; they are in effect a teleport), you will find yourself in front of the house, in the gardens.
As of the 9 June, 2009 update the Rat Catchers guards have had their field of view reduced to 100 degrees.
 Getting Inside the House To make your way inside the house you will need to make sure you don't draw the guard's attention; running permanently is advised and much patience will help greatly. Guards will not notice your cat.
There are three "safe points"; upon reaching these points, any guards who see you will send you back to these points, rather than the beginning.
From the start:
Wait until the guards are next to each other at the bridge, and run south of the hedges to the west. Then run north and hide at the hedges directly west of the mansion. Run the North-west corner when the guard is behind the hedges. Then run to the hedges directly north of the mansion. From here, run to a nearby trellis and climb up.
balcony, move as close as possible to a potted plant on the right and wait for the guards to move away. Hide by the Potted PlantGo inside the west bedroom to find and have your cat kill the first rat. Find your way into the opposite bedroom across the hall and wait. Be patient, and when one guard disappears from sight walking on the balcony and the other has his back turned, enter the big room with rats two and three and have puss kill them. Down the ladder in the same room you are in, are two more rooms - the first with one rat, the second with two (rats four, five, and six) - all without guards. NOTE: if your cat gets stuck in the wrong room, you can use the 'Call' button from the summoning menu to get it back into the same room with you.