Missing value imputations using Amos

I am currently working on a data set with 500 cases that has data MAR. I have data MAR, across 100 odd items. I am aware of the Select mean and intercept option in amos for imputing data.
Specifically, How does one impute the data for all cases. Is there any website or reference that states how this is carried out? I have read thu the user guide and the book by Byrne 2001, but steps on imputation are not explicity outlined.
Would appreciate some suggestions on the same