Decrease Size of an Unity Project

One of my Unity Dev build an Unity3d project as per requirements. All complete except the build size of WebGL & Android is too high. He said, it is needed to decrease the size of assets, texture, mesh etc. But he can't do it. I have purchased a room asset from Unity asset store. It's size is huge. So, the size should be decreased for faster loading specially for WebGL. Also, I need to create two animated character (Female & Male, Indian or Bangladeshi look with Saree or Salwar Kamiz) for the same project. I will provide all the Unity project data of current project including source. It's an ongoing job. You'll maintain the project time to time. I'll pay for that. Besides, I have more Unity projects if it is done nicely. You'll always work with our team remotely. Good opportunity. I need an expert to handle. No time wasters. I have very limited time. If you think you can do this with quality, place bid. Write the word "Unity WebGL" at the end of your bid application.