Hello,
Yes, we can help you to modify/upgrade your existing site.
Kindly share your existing site URL & requirements in detail so that I can get a clear idea about the total scope of the job.
We have very good experience in website designing and development using Angular, React, Node, WordPress, PHP, Laravel, CodeIgniter, CakePHP, MySQL, Ajax, HTML5, CSS3, Bootstrap, jQuery, JavaScript, etc...
Let's discuss more details...
Regards
Sukanta