When approaching a roundabout select the appropriate lane in plenty of time. You then approach at a speed that you can easily stop if necessary, drive smoothly through if clear.
Unless road markings dictate otherwise if the exit is past 12 O'Clock then indicate right on approach, enter on the right, then after passing the exit just before your exit, check mirrors quick shoulder check, indicate, change lanes and exit in the left hand lane or left hand side if no lane.
Few Irish Myths regarding Roundabouts
1. You can not change lanes on a roundabout?
If that was true there would be only one useable lane on a roundabout - the outside one. You treat a roundabout same as any other part of the road network, maintain lane displine but if necessary change lanes. (After due observations etc.)
2. You must exit same lane that you entered ???
In keeping with the basic rules of the road, you normally exit in the left hand lane, irrespective which lane you entered on. But if for example you are turning right a short distance ahead then you may exit in the right hand lane.