The Canadian Aviation Regulations list the requirements for certifying or changing aeronautical products. The regulations also define a minimum expectation of technical capability required by an applicant or delegate to support the required technical aspects of applying for a type design change.
More information on the supplemental type design process
If you don’t have the required technical abilities, you should source that capability to support your application. One place to look is a Transport Canada delegated Design Approval Organization (DAO) or a Design Approval Representative (DAR).
These people and organizations have various technical capabilities and can also act on behalf of Transport Canada to support you in the certification process, including issuing certain types of approvals.