The screening process is based on the inclusion and exclusion criteria that you outlined in the protocol. Start by screening titles and abstracts.  You will then need the full text of an article for more detailed screening.

In order to reduce the risk of selection bias, it is important to have a team of at least two or three reviewers. To ensure faster and more accurate screening, it is recommended that the team do a pilot screening first to identify any difficulties with the inclusion and exclusion criteria. It is also important to report how many reviewers screened at each stage (titel/abstract or full-text) and what process was used to resolve any disagreements.

• Rayyan is a free web/mobile app screening tool with some machine learning capability
• Section 4.6.3: A typical process for selecting studies from the Cochrane Handbook for Systematic Reviews of Intervention
• Templates for the PRISMA flow diagrams used to indicate the number of studies found and removed at the various screening stages