You can try converting the script to pdf (if it isn't already) and then compressing the pdf in order to reduce the file size at ShrinkPDF. (It's free.)

If this doesn't work, or you're purchasing a service that requires an editable file, such as Margin Notes or a Line Edit, then please send us the script to submissions [at] scriptreaderpro [dot] com. 

The length of the script may be the issue, though, so please make sure it falls within our page count recommendations too. 

If you still need help, please contact us.