merge learning objects into one user-files folder

I have various xerte installations in which user-files contain different learning objects with different names.
I would like to merge them without first exporting them all and then importing them again later. If I rename them, are they automatically read in or does an index have to be adjusted and is that possible directly in a file?
For example, I currently have the following learning objects:
49-loe-Nottingham
6-guest2-Nottingham
5-loe-Nottingham
51-loe-site
The Xerte installation that I want to use further is that of ...- guest2-Nottingham.

Like advice and suggestions.
Ronald van Loenen.