You have to work for a company that has the procedure in place and approved by the NRA of the company in question for the On The Job Training. It is not a course.. It is do the tasks under the supervision of an OJT trainer that is approved as such by the company. You have to do 50% of the tasks listed by the OJT package that the 145 company has produced from the Annex list in PART 66. You do the job on actual aircraft and actual tasks and it is recorded on the OJT sheets with the details from the work pack or tech log. You may if you are lucky get it done in a year, Hopefully 2 years.. It may take you 4 years like me and I had to do the full type course and practical elements again (2 years of that was waiting for the company to sort the OJT procedure out and a year before I could seriously get any OJT sorted out!). It is not a give it to me course, you learn the type and earn the rating!