Loop Editor can natively open and save AIFF, WAV, Apple Loops, ACID, and Sound Designer II files. Loop Editor can also import and convert ReCycle (REX and RX2) files to Apple Loop or ACID files.
You can add files to the File List by selecting File > Add...
Which will then prompt the open dialogue:
Or, you can add files to the File List via drag and drop.
To add ReCycle files to the File List you first need to install the REX Shared Library. If the REX Shared Library is not installed, you will be confronted with this dialogue upon launching Loop Editor:
For download and installation instructions visit Propellerhead's REX Shared Library page.
Loop Editor will convert the ReCycle file to either an Apple Loop or ACID file. Select Loop Editor > Preferences to specify the conversion behavior. See the "Preferences" chapter for more information.
After you've edited a file a blue dot will appear next to it.
Select File > Save to save the file in its original format.
Finally, you will want to export the files as ACID and/or Apple Loop files.
First, select the files in the File List you wish to export.
Then select File > Export.
Specify the export location and file formats you wish to export as, then select "Choose."