The steps are: create an account, complete identity verification, complete and submit the application, wait for the Center to accept it, and then for examination, after which the certificate issues. Examination normally finishes within 60 days of acceptance.
You will generally need the application form, the software identification materials (source code and documentation), proof of the applicant's legal status, and whatever evidence of ownership the case calls for. For source code, submit the first 1,500 and the last 1,500 lines — 3,000 in total. Where the program runs to fewer than 3,000 lines, submit all of it. The documentation should describe the software fully, in text supported by screenshots.
What you put on the application becomes the foundation of any later enforcement, so it has to match the facts.