yes it can be done in a sim, but if you are converting it, it has to be with a JAA Flight Ops Inspector, and you have to book it 3 months in advance.
If you got more than 500 on type, you just need an LST, anything less you have to do a course, but i think the course can be reduced, probably just a recurrent.
I have done this process last year, so if anybody needs any advice please PM me.