How to replace item in LQC?

I have Lazy Query Container (LQC) + hibernate connected to table. I don’t want to display some co collection at the table so some collections are lazy loaded.
When user select item (row) in table I want to open edit form with all data available. I have to initialize selected item - I get entity from Item, merge it back to context and call hibernate.initialize. it works fine, collections are initialized. But it is another instace then instance in item (because merge returns new instance)

How can I replace non-initialzied item with this new one?

Or how can I refresh the container and the table (how to select previously selected row in table after refresh?)