How can I get a higher alcohol content with coopers LME kits ?

This question should probably have been asked before but I did 2 searches and didnt bring an answer. What are some good ways to get a higher alcohol content with the coopers kits without affecting the flavor of the beer very much ? Ive heard to just add more fermentable sugars or extra DME but seems like most of the coopers kits are designed to have around a 3 to 5% alcohol content , and that " may " mean the yeast provided are not very alcohol tolerant. Anyway , if you have some experience with this I would love to hear about it. thanks

Just add a (1lb) bag of DME the lightest you can find.

like said above add another pound of DME.

little advice would be to buy a better yeast though. something like us-05 from safale would do the trick.