Fork this repository. If you have an existing fork from before, pull and merge upstream changes.
Add token entries to the json and add token logos to the repo if you do not have them hosted at an external location, and add the logo link to your json entries by following the existing examples.
Raise the "major" version number at the start of the json file by 1.
Validate your token list through https://jsonlint.com/ , and take a screenshot. Fix your errors if the json is invalid.
Create a PR from your fork to our original repo. Make sure to enable the option "Allow edits by maintainers" while putting up the PR.
Make sure to attach the screenshot of the validation results from jsonlint in your PR
All of the necessary steps can also be done through the GitHub Web UI.