You are wrong! The RNC does have a partisan voter registration manual...
For volunteers who would like to participate in, or undertake, voter registration and turnout programs, the national party offers a manual of best practices called the 7 Steps to 72-Hour Success. The manual highlights seven proven methods for reaching potential voters, including using volunteer and paid programs to target, locate, contact and register eligible voters. Effective tactics such as door-to-door contact, telephone and mail programs also are included.
from: RNC Site