Task for modifying WordPress/Shopify websites

I currently have a large number of websites that need to be adjusted. I need the assistance of a developer who is proficient in WP development and Shopify. I need to modify at least 4-5 websites every day. I will provide a document for each modification as a guide. Most of the changes are details and adjustments to the UI layout. There are very few functional developments. Therefore, the requirements for front-end development are quite high. The budget I offer is 100 per week, with two milestones. I will pay 50 on the first 4 days. If the cooperation is satisfactory, I will activate the second milestone and pay the remaining fees. What I need is a long-term cooperative developer who can work quickly in the WP system. We will give priority to developers who can work quickly in the WP system and are willing to work full-time, with sufficient working hours each day. If the cooperation goes smoothly in the early stage, I can increase the budget later. My only requirement is: the speed must be fast, and the developer must be able to complete the modification of each website quickly according to the documents provided to us.