TypeScript team member Daniel Rosenwasser provided instructions for replacing the TypeScript compiler and language service used by Visual Studio here:
https://github.com/Microsoft/TypeScript/issues/1110#issuecomment-62451204
He also described how to update the lib.d.ts file later in the same issue:
https://github.com/Microsoft/TypeScript/issues/1110#issuecomment-65865932
These instructions are not guaranteed to work, so be sure to back up your original files.