The article provides a step-by-step guide on how to finetune large language models like GPT on a custom dataset using the Lit-GPT implementation. It covers installation, model weight download, data preparation, and finetuning. The tutorial uses the RedPajama-INCITE model and the Dolly 2.0 instruction dataset as examples. The goal is to adapt the model to a specific task, such as training a chatbot to answer financial questions.