A lighting circuit is usually arranged like a string (not a ring) starting at the consumer unit and wandering round the house from one ceiling rose to the next (hopefully with no hidden junction boxes)
If you can identify the route the cable takes, you can draw a diagram, and start with the nearest rose to the CU, and see if that is correct. If so, go to the next one and so on.
You will have to identify every wire in every ceiling rose to do this, and mark them. although there will be reds and blacks, some of them will be supply in, some of them will be supply out, sone of them will be to and from the switch. You can't tell by the colour.
Read the Wiki on lighting circuits until you are sure you understand.
//www.diynot.com/wiki/electrics:lighting
you will need:
A multimeter
Some white vinyl tape and a permanent marker for labelling each wire
some green and yellow sleeving
some red sleeving
notebook
Some 1.5m T&E cable to replace any damaged sections
some cable clips
If you take a light fitting apart without careful labelling and understanding, you will probably reconnect it wrong.
If you get in a muddle, I recommend you find a better electrician.