If there really is a project that you need to have write access on (and only then), you have to register. After that you should ask the administrator of the project to give you access rights.
If you still think you need to register, please contact Javier.Serrano (insert a "@" here) cern.ch by sending a him or one of the other OHWR administrators your Name, Username and E-mail.
The repositories are used to store full hardware design information and
source files of firmware and software. Someone who likes to continue a
development should be able to check out a Repository and have all needed
information. Here are a couple of example policies currently used in OHR
projects for handling contributions: