Scania, one of the heavy engines manufacturers, produces Scania Diagnos Programmer 3 (SDP3) to facilitate repair process in their workshops. SDP3 is localizable software which challenges to separate User Interface strings (UI strings) during development process and later combine with the localized strings for local user access. The objective of this report is to provide knowledgeable solution for Graphical User Interface (GUI) development, especially with respect to synchronization of UI strings in SDP3.The migration of SDP3 from .NET 3.0v framework to .NET 3.5v framework satisfies modern standards and needs. With regards to migration of SDP3’s localization process, I have attempted to summarize major .NET 3.5v framework methods that can be used for localization of GUI text in SDP3. Experiments show that tools used to facilitate the localization process also lack important features. Although pre-build process and post-build process provide promising solutions for localization, using them along with some proprietary localization tool should result in more features, better and faster production cycle. However, proprietary localization tool have to be used with anyone of the localization methods.