You need to gain and understanding of the relationship between the "USER Bank", and the "LIBRARY Banks"... The USER Bank is like your assembly area (your work area). You can assemble as many as 640 Performances in the User Bank. A collection of 640 User Performance can then be SAVED in a FILE called a LIBRARY FILE (.X7L). It is that FILE that writes you data into memory in the organized fashion that you will ultimately want. First you can just place all the Motif XF/MOXF data into a Library... then decide what it is you want to keep... Keep the good stuff by IMPORTING it to USER... assemble your keeps from both Files by Importing from there temporary location. Once all assembled create your own customized Montage version of the data. Finally, install that data

The following is taken from an article here on YamahaSynth that explains that difference: but this is the gist of what you will need to do - read the article for the details:

(From the article: Master MONTAGE: Montage USER and LIBRARY Files)
You can load the Motif XF data (.X3A, .X3V, .X3E), MOXF data (.X6A, .X6V, .X6E) directly to a Montage Library slot by selecting "Contents Type" = Library File. Everything that is necessary to make it play will be installed. You can then audition the sounds, decide which ones you think are "keepers". The ones you want to keep you can IMPORT to the USER Bank.

Why would you want to import them into USER? Because you assemble the data that you want to keep and then create your own custom library. You may only like half of the sounds in the Library you've purchased or downloaded, you can pick which ones you like, move them into your USER area, assemble them, edit them and customize them, then ultimately WRITE (save) your own LIBRARY FILE. Use it to take the place of the one you initially installed to audition.

Montage will handle all the heavy-lifting, managing the data behind the scenes. The IMPORT LIBRARY function alerts the system to keep track of the Waveform/Sample data in addition to the Performance parameters that use that data. It does so by meticulous going through and repointing each PART to a USER Bank version of the WAVEFORM data. If you do not use the IMPORT LIBRARY function, you may lose the relationship between the PART and its Waveform/Samples. The act of "importing" is more significant than just calling up a Library Performance and storing it to internal. The act of importing includes the link between the PERFORMANCE PART and its Waveform data. And you are going to write in a new location for that data!

So a good practice when purchasing a Library or simply trying out new data, is to load it into the Library area to audition it, pick the data you like, then using the "Import Library" function assemble the "keeper data" into your (initialized) User area... Create your own custom Library file... Finally, install it and then clear the waste by deleting...

Thanks for the info bad mister!!