As a lurking instructor need some info on how to get certified by UKCAA. Tried the website without much luck. Can anyone assist me please

There is now no such thing as a '509 Instructor'. All that is required to train students to commercial level is to under go a course with the standards flight of the school or college where you will be teaching. This is the new system under JAR. Also, the level of experience has reduced considerably, most colleges will look at an FI with only 200hrs instructional time. Good Luck!