Unless the change is trivial, you need to educate the project members about the new Development Process, including any guidelines, templates and/or tools. This can vary from an informal 2 hour presentation to more formal training, depending on the size of the project and the project members' familiarity with similar development processes.
The following are commonly used ways to educate the project members:

• Briefing
  If the change is small or easy to understand a briefing to the team may be sufficient.
• Mentors
  Having experienced mentors or consultants on the project or available to the project is an effective way to provide guidance on an as-needed basis.
• Workshop
  A one day process adoption workshop (PAW) for all project members can help "kick-start" a new or significantly changed process. See Guidelines: Process Adoption Workshop
• Customized training courses.
  If the project member have not attended the standard training courses in process and tools, an alternative is to customize the standard training courses, to cover the project's development process, including guidelines, templates and tools. However, it can be expensive to customize training courses. Generic process training, like an introductory course to the Process or one or more practices, should be conducted prior to project startup, or in the early days of the project. More specialized training in techniques, methods or technologies, is often conducted "just-in-time". This means that the training is given shortly before the method or technique is to be applied in the project, to ensure that new knowledge is fresh in mind. "Boot-camps".
• 1-5 weeks of concentrated hands-on training. Not many organizations can afford to arrange these kinds of boot-camps, but they have proven to be efficient if there are many new factors for the people in the project. A boot-camp is typically a mixture of seminars, training courses and hands-on work with the process and tools.