call this number at USEM, 1-909-101-7878. get you case number ready, they'll ask for it. if your papers are in the USEM, you can schedule for your interview. they will send you a confirmation letter via email. you can present that letter to SLEC for your medical appointment.
you may go to the medical appointment maybe 2 weeks prior to the interview. bring immunization records, xray film more than 3 months old, medical certificates if you underwent operations, if you have them.
I went to SLEC around 12.30pm on the first day, finished at 5.30pm. some went there at 6-7am then finish around 5-6pm also..
goodluck and congratulations, you are a step closer.