I don't think 7 months will be counted as employment period.
VISA transfer can take same time period as a new H1B petition (approx. 2-6 months). If you go for Premium Processing, you could get adjudication done in 15 calendar days.
Process is same as new H1B petition filing - you need to find an employer who has a job for you and they will do the filing formalities. You need to provide them with all required documents including the approved H1B petition copy or approval notice.