Start by assembling the two halves of the model as per the instructions. As with the other Falcons, it's the base of the model in which most of the lighting is installed. With the two halves of the model more or less completed, now is also the time to consider a base coat for any colour washing for the weathering if required.
Your best friends for the modifications needed will be a 1mm drill, 3mm drill, 5mm drill, flush cutters and some good tin snips.
Consider how the model will be supported (eg using the stand supplied or a modified stand of your own), and drill a 3mm hole through which to run the main power lead - the light kits can be taken apart at the terminal connector to allow this to be run through the model.
Once done, the led supports supplied in the kit need to be widened to 5mm - carefully, preferably by securing them in a vice and not drilling through your hands (getting blood stains out of the colour washing can prove tricky) - and fit these in place on the rear engine mounts.