Okay so I should pick up a few 555 Circuit?
Right now I have the power coming from a 24v power source and into a toggle switch out of that into a resistor and out to the lights.
So for the potentiometer to work as a dimmer, I would have the power going into the circuit and out of the circuit to the sliding potentiometer and from there out to the lights?
The sentence I have highlighted above in
red is the only thing that makes any sense so far.
To vary the intensity of your LEDs you need to vary the effective current your power source and resistor provides. The most simple and efficient way to do this is to turn the power off and on very rapidly, thousands of times per second, while being able to vary the "on" time to "off" time ratio with your slider potentiometer. To do that requires a pulse-width modulated power control with a potentiometer control input to provide a variable constant-current output to the LEDs. It would be inserted in series with your power source, toggle switch, and LEDs. The resistor would not be needed.
These devices are available all over the Internet from (usually) Asian sources.
Here is one offered by Amazon for four bux American. Try looking on the UK Amazon website. If you insist on using your slider potentiometer, it will have to replace the existing potentiometer in the dimmer control box.
Look on this Google page for other versions.