here's the basics of it: generate the orphans from the meta data:

/*--Results

ALTER USER [z_AppDB_reports] WITH LOGIN = [z_AppDB_reports];

ALTER USER [medical] WITH LOGIN = [medical];

*/

SELECT 'ALTER USER ' + quotename(dbloginz.name) + ' WITH LOGIN = ' + quotename(svloginz.name) + ';'

from sys.database_principals dbloginz

LEFT OUTER JOIN sys.server_principals svloginz

on dbloginz.name = svloginz.name

WHERE dbloginz.type IN ('S')

AND dbloginz.name NOT IN('dbo','guest','INFORMATION_SCHEMA','sys')

and svloginz.name is not null and dbloginz.sid <> svloginz.sid

to do it as a single script, server wide, you'd have to add a cursor i guess, but it's certainly doable.