Well, modifications to the kit would depend on whether you'd like to make a "Cooper's Pale Ale" or simply just "a pale ale".
If you'd like a Cooper's style pale ale:
Reculture yeast from a real Cooper's beer. Temperature control during fermentation is then critical - *under* 18c in my opinion.
Brew Enchancer 2 (easy) or an equivalent - eg. 750g light dry malt, 250g dextrose, 250g steeped Carapils.
No extra hop additions. The can will provide all the bitterness you need and the Cooper's yeast will chainsaw through the malt and bring the hops out more than you'd expect.
If you'd like a pale ale:
Use whatever yeast you like, suggest US-05, but even the can kit yeast kept low (18-20c) will produce good results.
I'd still use the BE2 or a full 1KG LDME with 250g steeped Carapils, maybe a touch (100g) of crystal malt as well.
A late aroma hop addition, something like EK Goldings. Boil the BE2/sugars/carapils liquid (not the can) with the hop pellets. 14g each at 15 and 5mins say.
One isn't necessarily better than the other, they're just different. A good example of the amount of variation you can get out of a can kit really.