integration of new Theme into an existing Laravel 8 Project

hi, i have an existing laravel 8 project, i have already integrated the new theme into many pages of my web app. i have already made new layouts, scripts, pages for new theme. you need to integrate the new theme into three pages, these pages are currently using old css and js files, you need to adjust the new theme layout in to these 3 pages so that the functionality of these 3 pages must work as it is working currently with old theme