With the internal record itself: dated procedure documents, development history, training material and results. Attribution matters as much as the document, because a petition names a person rather than a capability.
Build the technical file before the legal one
Start with the procedure as written down internally, including earlier versions, so that development over time is visible on the page. Add the material showing the named employee's part in creating or advancing it: design notes, laboratory or field data, internal reports, correspondence approving a change, and records of the training he delivered to colleagues. Include customer outcomes the procedure produced where those can properly be shared. Then supply the comparison: the published standard or the commercially available method, with a short explanation of the difference and why it matters commercially. Support all of that with ordinary corporate evidence, including incorporation and share records for both entities, financial statements showing each is trading, and payroll for the qualifying year. Confidential material can be described and, where necessary, redacted rather than withheld entirely.
Hypothetical example: a custom dental-milling firm keeps its design rules in a controlled repository, while the proposed transferee has only a generic résumé. The first review should index release notes, access logs, internal training, client implementation reports, and the employee's role in each document. Repository history supports the process; payroll supports the foreign employment. Preserve the original dates before preparing a narrative. A typical mistake is producing a polished technical letter without records connecting the worker to the claimed proprietary knowledge or to the U.S. work that needs it.