If it is a Hytec dimmer send to me and I will repair for you 07514874120
Paul
June 2016
You do not say what's wrong with the dimmer and you do not describe any details of the lamp so a sensible answer is somewhat difficult.
In brief - dismantle the lamp - extract the dimmer - find a replacement dimmer - it need not be exactly the same - just one that fits and can manage the load - and put it all back together.