Went into Roi Et Immigration yesterday for my first 1year extension on O visa based on marriage. Was thinking it might a bit difficult reading some reports but very very easy and fast about 1hr.45 . My passport with photocopies of all pages with stamps in and front page 2 passport size photos of me wife's ID and house book photos off us outside and 2 inside house and map from immigration to home from goggle TM7 that i printed at home and filled out I have a photocopier did it all at home .Then up datetd marriage certificate in and out 8mins then3 months bank statements and letter update bank book 20mins then to immigration got under consideration stamp go back 28 January but not difficult at all and very helpful.