After saving the application pdf to your computer, open it with Adobe Acrobat and fill it out.
After filling it out save it to your computer ( It is very important that the document is saved correctly)
If it is easier for you feel free to print it out and bring it in when your ready for your interview ( before you come in for an interview call the office and schedule or schedule online and reference the hiring requirements form so you are aware of all the documents you must bring to the office when you are ready to be interviewed.
After saving to your computer, upload it using the upload field for the corresponding form, fill out the form and the rest of the pdfs on the website the same way and click the submit button towards the bottom of the apply page when finished.
EXCEPTION! The I-9 form is a printable pdf, so if you want to upload it with the rest of your documents then you must print it off, fill it out, scan it, then upload it.