Move over Oracle hello MS

[GBH123]

I need your help, I have a candidate (yes I am a Recruiter but new to IT) who has 15 years experience of developing in oracle. Particularly SQL and PL/SQL. He wants to move over to SQL Server and MS however most clients will not look at assisting in the training required. For those out there those have changed from one to the other please could you tell me how you went about it and how difficult it was?

Thank you in advance