Then import into your main file: 

1. Click File/Open (CTL+O) 
2. This bring up the Open Family File Dialog, which has lots of options: 
• The file in the File Name space is the one which will be opened. You can enter the name directly, or use some of the other options to locate the file you want. 
• The window shows a selection of file choices. If you highlight one, it will pop into the File Name space. 
• Below the File Name space is a pulldown menu of allowable file types, including all the various FTM types, GEDcoms, &c. Only files of the selected type will appear in the window. 
• The pulldown at the top shows the folder being displayed in the window. You can navigate to another folder on the pulldown map. 
• Next to the navigation pulldown is a little folder icon with an up-arrow. Use this to navigate to the next superior folder. 
• You can use the Find button to search for the file you want.
3. Once you find and select the file you want, you can either Open or Append it: 

 OPEN

Abandons the contents of the current workspace, which is safely tucked away in its file first, replacing it with the name and content of the selected file.

APPEND

Keeps the current contents (and name) of the current workspace, adding the contents of the selected file. You will be given a further option to change the Append to a Merge.

MERGE

Identical to Append except, in addition, attempts will be made to find identical individuals to combine.